1 | |
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2 | /* pngrtran.c - transforms the data in a row for PNG readers |
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3 | * |
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4 | * libpng 1.2.5 - October 3, 2002 |
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5 | * For conditions of distribution and use, see copyright notice in png.h |
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6 | * Copyright (c) 1998-2002 Glenn Randers-Pehrson |
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7 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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8 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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9 | * |
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10 | * This file contains functions optionally called by an application |
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11 | * in order to tell libpng how to handle data when reading a PNG. |
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12 | * Transformations that are used in both reading and writing are |
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13 | * in pngtrans.c. |
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14 | */ |
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15 | |
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16 | #define PNG_INTERNAL |
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17 | #include "png.h" |
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18 | |
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19 | /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
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20 | void PNGAPI |
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21 | png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) |
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22 | { |
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23 | png_debug(1, "in png_set_crc_action\n"); |
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24 | /* Tell libpng how we react to CRC errors in critical chunks */ |
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25 | switch (crit_action) |
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26 | { |
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27 | case PNG_CRC_NO_CHANGE: /* leave setting as is */ |
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28 | break; |
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29 | case PNG_CRC_WARN_USE: /* warn/use data */ |
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30 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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31 | png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
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32 | break; |
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33 | case PNG_CRC_QUIET_USE: /* quiet/use data */ |
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34 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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35 | png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
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36 | PNG_FLAG_CRC_CRITICAL_IGNORE; |
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37 | break; |
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38 | case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ |
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39 | png_warning(png_ptr, "Can't discard critical data on CRC error."); |
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40 | case PNG_CRC_ERROR_QUIT: /* error/quit */ |
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41 | case PNG_CRC_DEFAULT: |
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42 | default: |
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43 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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44 | break; |
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45 | } |
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46 | |
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47 | switch (ancil_action) |
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48 | { |
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49 | case PNG_CRC_NO_CHANGE: /* leave setting as is */ |
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50 | break; |
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51 | case PNG_CRC_WARN_USE: /* warn/use data */ |
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52 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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53 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; |
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54 | break; |
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55 | case PNG_CRC_QUIET_USE: /* quiet/use data */ |
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56 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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57 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | |
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58 | PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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59 | break; |
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60 | case PNG_CRC_ERROR_QUIT: /* error/quit */ |
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61 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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62 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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63 | break; |
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64 | case PNG_CRC_WARN_DISCARD: /* warn/discard data */ |
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65 | case PNG_CRC_DEFAULT: |
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66 | default: |
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67 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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68 | break; |
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69 | } |
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70 | } |
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71 | |
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72 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
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73 | defined(PNG_FLOATING_POINT_SUPPORTED) |
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74 | /* handle alpha and tRNS via a background color */ |
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75 | void PNGAPI |
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76 | png_set_background(png_structp png_ptr, |
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77 | png_color_16p background_color, int background_gamma_code, |
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78 | int need_expand, double background_gamma) |
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79 | { |
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80 | png_debug(1, "in png_set_background\n"); |
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81 | if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) |
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82 | { |
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83 | png_warning(png_ptr, "Application must supply a known background gamma"); |
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84 | return; |
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85 | } |
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86 | |
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87 | png_ptr->transformations |= PNG_BACKGROUND; |
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88 | png_memcpy(&(png_ptr->background), background_color, sizeof(png_color_16)); |
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89 | png_ptr->background_gamma = (float)background_gamma; |
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90 | png_ptr->background_gamma_type = (png_byte)(background_gamma_code); |
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91 | png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); |
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92 | |
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93 | /* Note: if need_expand is set and color_type is either RGB or RGB_ALPHA |
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94 | * (in which case need_expand is superfluous anyway), the background color |
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95 | * might actually be gray yet not be flagged as such. This is not a problem |
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96 | * for the current code, which uses PNG_BACKGROUND_IS_GRAY only to |
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97 | * decide when to do the png_do_gray_to_rgb() transformation. |
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98 | */ |
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99 | if ((need_expand && !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) || |
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100 | (!need_expand && background_color->red == background_color->green && |
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101 | background_color->red == background_color->blue)) |
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102 | png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
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103 | } |
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104 | #endif |
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105 | |
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106 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
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107 | /* strip 16 bit depth files to 8 bit depth */ |
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108 | void PNGAPI |
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109 | png_set_strip_16(png_structp png_ptr) |
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110 | { |
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111 | png_debug(1, "in png_set_strip_16\n"); |
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112 | png_ptr->transformations |= PNG_16_TO_8; |
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113 | } |
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114 | #endif |
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115 | |
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116 | #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
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117 | void PNGAPI |
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118 | png_set_strip_alpha(png_structp png_ptr) |
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119 | { |
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120 | png_debug(1, "in png_set_strip_alpha\n"); |
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121 | png_ptr->transformations |= PNG_STRIP_ALPHA; |
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122 | } |
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123 | #endif |
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124 | |
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125 | #if defined(PNG_READ_DITHER_SUPPORTED) |
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126 | /* Dither file to 8 bit. Supply a palette, the current number |
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127 | * of elements in the palette, the maximum number of elements |
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128 | * allowed, and a histogram if possible. If the current number |
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129 | * of colors is greater then the maximum number, the palette will be |
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130 | * modified to fit in the maximum number. "full_dither" indicates |
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131 | * whether we need a dithering cube set up for RGB images, or if we |
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132 | * simply are reducing the number of colors in a paletted image. |
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133 | */ |
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134 | |
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135 | typedef struct png_dsort_struct |
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136 | { |
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137 | struct png_dsort_struct FAR * next; |
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138 | png_byte left; |
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139 | png_byte right; |
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140 | } png_dsort; |
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141 | typedef png_dsort FAR * png_dsortp; |
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142 | typedef png_dsort FAR * FAR * png_dsortpp; |
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143 | |
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144 | void PNGAPI |
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145 | png_set_dither(png_structp png_ptr, png_colorp palette, |
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146 | int num_palette, int maximum_colors, png_uint_16p histogram, |
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147 | int full_dither) |
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148 | { |
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149 | png_debug(1, "in png_set_dither\n"); |
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150 | png_ptr->transformations |= PNG_DITHER; |
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151 | |
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152 | if (!full_dither) |
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153 | { |
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154 | int i; |
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155 | |
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156 | png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, |
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157 | (png_uint_32)(num_palette * sizeof (png_byte))); |
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158 | for (i = 0; i < num_palette; i++) |
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159 | png_ptr->dither_index[i] = (png_byte)i; |
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160 | } |
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161 | |
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162 | if (num_palette > maximum_colors) |
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163 | { |
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164 | if (histogram != NULL) |
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165 | { |
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166 | /* This is easy enough, just throw out the least used colors. |
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167 | Perhaps not the best solution, but good enough. */ |
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168 | |
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169 | int i; |
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170 | |
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171 | /* initialize an array to sort colors */ |
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172 | png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr, |
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173 | (png_uint_32)(num_palette * sizeof (png_byte))); |
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174 | |
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175 | /* initialize the dither_sort array */ |
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176 | for (i = 0; i < num_palette; i++) |
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177 | png_ptr->dither_sort[i] = (png_byte)i; |
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178 | |
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179 | /* Find the least used palette entries by starting a |
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180 | bubble sort, and running it until we have sorted |
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181 | out enough colors. Note that we don't care about |
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182 | sorting all the colors, just finding which are |
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183 | least used. */ |
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184 | |
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185 | for (i = num_palette - 1; i >= maximum_colors; i--) |
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186 | { |
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187 | int done; /* to stop early if the list is pre-sorted */ |
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188 | int j; |
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189 | |
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190 | done = 1; |
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191 | for (j = 0; j < i; j++) |
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192 | { |
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193 | if (histogram[png_ptr->dither_sort[j]] |
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194 | < histogram[png_ptr->dither_sort[j + 1]]) |
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195 | { |
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196 | png_byte t; |
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197 | |
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198 | t = png_ptr->dither_sort[j]; |
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199 | png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1]; |
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200 | png_ptr->dither_sort[j + 1] = t; |
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201 | done = 0; |
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202 | } |
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203 | } |
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204 | if (done) |
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205 | break; |
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206 | } |
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207 | |
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208 | /* swap the palette around, and set up a table, if necessary */ |
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209 | if (full_dither) |
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210 | { |
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211 | int j = num_palette; |
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212 | |
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213 | /* put all the useful colors within the max, but don't |
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214 | move the others */ |
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215 | for (i = 0; i < maximum_colors; i++) |
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216 | { |
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217 | if ((int)png_ptr->dither_sort[i] >= maximum_colors) |
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218 | { |
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219 | do |
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220 | j--; |
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221 | while ((int)png_ptr->dither_sort[j] >= maximum_colors); |
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222 | palette[i] = palette[j]; |
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223 | } |
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224 | } |
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225 | } |
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226 | else |
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227 | { |
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228 | int j = num_palette; |
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229 | |
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230 | /* move all the used colors inside the max limit, and |
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231 | develop a translation table */ |
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232 | for (i = 0; i < maximum_colors; i++) |
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233 | { |
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234 | /* only move the colors we need to */ |
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235 | if ((int)png_ptr->dither_sort[i] >= maximum_colors) |
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236 | { |
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237 | png_color tmp_color; |
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238 | |
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239 | do |
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240 | j--; |
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241 | while ((int)png_ptr->dither_sort[j] >= maximum_colors); |
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242 | |
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243 | tmp_color = palette[j]; |
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244 | palette[j] = palette[i]; |
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245 | palette[i] = tmp_color; |
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246 | /* indicate where the color went */ |
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247 | png_ptr->dither_index[j] = (png_byte)i; |
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248 | png_ptr->dither_index[i] = (png_byte)j; |
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249 | } |
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250 | } |
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251 | |
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252 | /* find closest color for those colors we are not using */ |
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253 | for (i = 0; i < num_palette; i++) |
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254 | { |
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255 | if ((int)png_ptr->dither_index[i] >= maximum_colors) |
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256 | { |
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257 | int min_d, k, min_k, d_index; |
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258 | |
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259 | /* find the closest color to one we threw out */ |
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260 | d_index = png_ptr->dither_index[i]; |
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261 | min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); |
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262 | for (k = 1, min_k = 0; k < maximum_colors; k++) |
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263 | { |
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264 | int d; |
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265 | |
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266 | d = PNG_COLOR_DIST(palette[d_index], palette[k]); |
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267 | |
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268 | if (d < min_d) |
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269 | { |
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270 | min_d = d; |
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271 | min_k = k; |
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272 | } |
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273 | } |
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274 | /* point to closest color */ |
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275 | png_ptr->dither_index[i] = (png_byte)min_k; |
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276 | } |
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277 | } |
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278 | } |
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279 | png_free(png_ptr, png_ptr->dither_sort); |
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280 | png_ptr->dither_sort=NULL; |
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281 | } |
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282 | else |
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283 | { |
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284 | /* This is much harder to do simply (and quickly). Perhaps |
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285 | we need to go through a median cut routine, but those |
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286 | don't always behave themselves with only a few colors |
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287 | as input. So we will just find the closest two colors, |
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288 | and throw out one of them (chosen somewhat randomly). |
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289 | [We don't understand this at all, so if someone wants to |
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290 | work on improving it, be our guest - AED, GRP] |
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291 | */ |
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292 | int i; |
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293 | int max_d; |
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294 | int num_new_palette; |
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295 | png_dsortp t; |
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296 | png_dsortpp hash; |
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297 | |
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298 | t=NULL; |
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299 | |
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300 | /* initialize palette index arrays */ |
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301 | png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, |
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302 | (png_uint_32)(num_palette * sizeof (png_byte))); |
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303 | png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, |
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304 | (png_uint_32)(num_palette * sizeof (png_byte))); |
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305 | |
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306 | /* initialize the sort array */ |
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307 | for (i = 0; i < num_palette; i++) |
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308 | { |
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309 | png_ptr->index_to_palette[i] = (png_byte)i; |
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310 | png_ptr->palette_to_index[i] = (png_byte)i; |
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311 | } |
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312 | |
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313 | hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * |
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314 | sizeof (png_dsortp))); |
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315 | for (i = 0; i < 769; i++) |
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316 | hash[i] = NULL; |
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317 | /* png_memset(hash, 0, 769 * sizeof (png_dsortp)); */ |
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318 | |
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319 | num_new_palette = num_palette; |
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320 | |
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321 | /* initial wild guess at how far apart the farthest pixel |
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322 | pair we will be eliminating will be. Larger |
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323 | numbers mean more areas will be allocated, Smaller |
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324 | numbers run the risk of not saving enough data, and |
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325 | having to do this all over again. |
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326 | |
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327 | I have not done extensive checking on this number. |
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328 | */ |
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329 | max_d = 96; |
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330 | |
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331 | while (num_new_palette > maximum_colors) |
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332 | { |
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333 | for (i = 0; i < num_new_palette - 1; i++) |
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334 | { |
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335 | int j; |
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336 | |
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337 | for (j = i + 1; j < num_new_palette; j++) |
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338 | { |
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339 | int d; |
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340 | |
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341 | d = PNG_COLOR_DIST(palette[i], palette[j]); |
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342 | |
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343 | if (d <= max_d) |
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344 | { |
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345 | |
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346 | t = (png_dsortp)png_malloc_warn(png_ptr, |
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347 | (png_uint_32)(sizeof(png_dsort))); |
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348 | if (t == NULL) |
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349 | break; |
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350 | t->next = hash[d]; |
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351 | t->left = (png_byte)i; |
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352 | t->right = (png_byte)j; |
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353 | hash[d] = t; |
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354 | } |
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355 | } |
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356 | if (t == NULL) |
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357 | break; |
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358 | } |
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359 | |
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360 | if (t != NULL) |
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361 | for (i = 0; i <= max_d; i++) |
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362 | { |
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363 | if (hash[i] != NULL) |
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364 | { |
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365 | png_dsortp p; |
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366 | |
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367 | for (p = hash[i]; p; p = p->next) |
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368 | { |
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369 | if ((int)png_ptr->index_to_palette[p->left] |
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370 | < num_new_palette && |
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371 | (int)png_ptr->index_to_palette[p->right] |
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372 | < num_new_palette) |
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373 | { |
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374 | int j, next_j; |
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375 | |
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376 | if (num_new_palette & 0x01) |
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377 | { |
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378 | j = p->left; |
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379 | next_j = p->right; |
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380 | } |
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381 | else |
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382 | { |
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383 | j = p->right; |
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384 | next_j = p->left; |
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385 | } |
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386 | |
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387 | num_new_palette--; |
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388 | palette[png_ptr->index_to_palette[j]] |
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389 | = palette[num_new_palette]; |
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390 | if (!full_dither) |
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391 | { |
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392 | int k; |
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393 | |
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394 | for (k = 0; k < num_palette; k++) |
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395 | { |
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396 | if (png_ptr->dither_index[k] == |
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397 | png_ptr->index_to_palette[j]) |
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398 | png_ptr->dither_index[k] = |
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399 | png_ptr->index_to_palette[next_j]; |
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400 | if ((int)png_ptr->dither_index[k] == |
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401 | num_new_palette) |
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402 | png_ptr->dither_index[k] = |
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403 | png_ptr->index_to_palette[j]; |
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404 | } |
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405 | } |
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406 | |
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407 | png_ptr->index_to_palette[png_ptr->palette_to_index |
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408 | [num_new_palette]] = png_ptr->index_to_palette[j]; |
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409 | png_ptr->palette_to_index[png_ptr->index_to_palette[j]] |
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410 | = png_ptr->palette_to_index[num_new_palette]; |
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411 | |
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412 | png_ptr->index_to_palette[j] = (png_byte)num_new_palette; |
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413 | png_ptr->palette_to_index[num_new_palette] = (png_byte)j; |
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414 | } |
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415 | if (num_new_palette <= maximum_colors) |
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416 | break; |
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417 | } |
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418 | if (num_new_palette <= maximum_colors) |
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419 | break; |
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420 | } |
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421 | } |
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422 | |
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423 | for (i = 0; i < 769; i++) |
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424 | { |
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425 | if (hash[i] != NULL) |
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426 | { |
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427 | png_dsortp p = hash[i]; |
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428 | while (p) |
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429 | { |
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430 | t = p->next; |
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431 | png_free(png_ptr, p); |
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432 | p = t; |
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433 | } |
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434 | } |
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435 | hash[i] = 0; |
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436 | } |
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437 | max_d += 96; |
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438 | } |
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439 | png_free(png_ptr, hash); |
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440 | png_free(png_ptr, png_ptr->palette_to_index); |
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441 | png_free(png_ptr, png_ptr->index_to_palette); |
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442 | png_ptr->palette_to_index=NULL; |
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443 | png_ptr->index_to_palette=NULL; |
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444 | } |
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445 | num_palette = maximum_colors; |
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446 | } |
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447 | if (png_ptr->palette == NULL) |
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448 | { |
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449 | png_ptr->palette = palette; |
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450 | } |
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451 | png_ptr->num_palette = (png_uint_16)num_palette; |
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452 | |
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453 | if (full_dither) |
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454 | { |
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455 | int i; |
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456 | png_bytep distance; |
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457 | int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + |
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458 | PNG_DITHER_BLUE_BITS; |
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459 | int num_red = (1 << PNG_DITHER_RED_BITS); |
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460 | int num_green = (1 << PNG_DITHER_GREEN_BITS); |
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461 | int num_blue = (1 << PNG_DITHER_BLUE_BITS); |
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462 | png_size_t num_entries = ((png_size_t)1 << total_bits); |
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463 | |
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464 | png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, |
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465 | (png_uint_32)(num_entries * sizeof (png_byte))); |
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466 | |
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467 | png_memset(png_ptr->palette_lookup, 0, num_entries * sizeof (png_byte)); |
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468 | |
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469 | distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
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470 | sizeof(png_byte))); |
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471 | |
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472 | png_memset(distance, 0xff, num_entries * sizeof(png_byte)); |
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473 | |
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474 | for (i = 0; i < num_palette; i++) |
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475 | { |
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476 | int ir, ig, ib; |
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477 | int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); |
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478 | int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); |
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479 | int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); |
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480 | |
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481 | for (ir = 0; ir < num_red; ir++) |
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482 | { |
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483 | int dr = abs(ir - r); |
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484 | int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); |
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485 | |
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486 | for (ig = 0; ig < num_green; ig++) |
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487 | { |
---|
488 | int dg = abs(ig - g); |
---|
489 | int dt = dr + dg; |
---|
490 | int dm = ((dr > dg) ? dr : dg); |
---|
491 | int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); |
---|
492 | |
---|
493 | for (ib = 0; ib < num_blue; ib++) |
---|
494 | { |
---|
495 | int d_index = index_g | ib; |
---|
496 | int db = abs(ib - b); |
---|
497 | int dmax = ((dm > db) ? dm : db); |
---|
498 | int d = dmax + dt + db; |
---|
499 | |
---|
500 | if (d < (int)distance[d_index]) |
---|
501 | { |
---|
502 | distance[d_index] = (png_byte)d; |
---|
503 | png_ptr->palette_lookup[d_index] = (png_byte)i; |
---|
504 | } |
---|
505 | } |
---|
506 | } |
---|
507 | } |
---|
508 | } |
---|
509 | |
---|
510 | png_free(png_ptr, distance); |
---|
511 | } |
---|
512 | } |
---|
513 | #endif |
---|
514 | |
---|
515 | #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
---|
516 | /* Transform the image from the file_gamma to the screen_gamma. We |
---|
517 | * only do transformations on images where the file_gamma and screen_gamma |
---|
518 | * are not close reciprocals, otherwise it slows things down slightly, and |
---|
519 | * also needlessly introduces small errors. |
---|
520 | * |
---|
521 | * We will turn off gamma transformation later if no semitransparent entries |
---|
522 | * are present in the tRNS array for palette images. We can't do it here |
---|
523 | * because we don't necessarily have the tRNS chunk yet. |
---|
524 | */ |
---|
525 | void PNGAPI |
---|
526 | png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) |
---|
527 | { |
---|
528 | png_debug(1, "in png_set_gamma\n"); |
---|
529 | if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) || |
---|
530 | (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) || |
---|
531 | (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
---|
532 | png_ptr->transformations |= PNG_GAMMA; |
---|
533 | png_ptr->gamma = (float)file_gamma; |
---|
534 | png_ptr->screen_gamma = (float)scrn_gamma; |
---|
535 | } |
---|
536 | #endif |
---|
537 | |
---|
538 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
---|
539 | /* Expand paletted images to RGB, expand grayscale images of |
---|
540 | * less than 8-bit depth to 8-bit depth, and expand tRNS chunks |
---|
541 | * to alpha channels. |
---|
542 | */ |
---|
543 | void PNGAPI |
---|
544 | png_set_expand(png_structp png_ptr) |
---|
545 | { |
---|
546 | png_debug(1, "in png_set_expand\n"); |
---|
547 | png_ptr->transformations |= PNG_EXPAND; |
---|
548 | } |
---|
549 | |
---|
550 | /* GRR 19990627: the following three functions currently are identical |
---|
551 | * to png_set_expand(). However, it is entirely reasonable that someone |
---|
552 | * might wish to expand an indexed image to RGB but *not* expand a single, |
---|
553 | * fully transparent palette entry to a full alpha channel--perhaps instead |
---|
554 | * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace |
---|
555 | * the transparent color with a particular RGB value, or drop tRNS entirely. |
---|
556 | * IOW, a future version of the library may make the transformations flag |
---|
557 | * a bit more fine-grained, with separate bits for each of these three |
---|
558 | * functions. |
---|
559 | * |
---|
560 | * More to the point, these functions make it obvious what libpng will be |
---|
561 | * doing, whereas "expand" can (and does) mean any number of things. |
---|
562 | */ |
---|
563 | |
---|
564 | /* Expand paletted images to RGB. */ |
---|
565 | void PNGAPI |
---|
566 | png_set_palette_to_rgb(png_structp png_ptr) |
---|
567 | { |
---|
568 | png_debug(1, "in png_set_expand\n"); |
---|
569 | png_ptr->transformations |= PNG_EXPAND; |
---|
570 | } |
---|
571 | |
---|
572 | /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
---|
573 | void PNGAPI |
---|
574 | png_set_gray_1_2_4_to_8(png_structp png_ptr) |
---|
575 | { |
---|
576 | png_debug(1, "in png_set_expand\n"); |
---|
577 | png_ptr->transformations |= PNG_EXPAND; |
---|
578 | } |
---|
579 | |
---|
580 | /* Expand tRNS chunks to alpha channels. */ |
---|
581 | void PNGAPI |
---|
582 | png_set_tRNS_to_alpha(png_structp png_ptr) |
---|
583 | { |
---|
584 | png_debug(1, "in png_set_expand\n"); |
---|
585 | png_ptr->transformations |= PNG_EXPAND; |
---|
586 | } |
---|
587 | #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ |
---|
588 | |
---|
589 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
---|
590 | void PNGAPI |
---|
591 | png_set_gray_to_rgb(png_structp png_ptr) |
---|
592 | { |
---|
593 | png_debug(1, "in png_set_gray_to_rgb\n"); |
---|
594 | png_ptr->transformations |= PNG_GRAY_TO_RGB; |
---|
595 | } |
---|
596 | #endif |
---|
597 | |
---|
598 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
---|
599 | #if defined(PNG_FLOATING_POINT_SUPPORTED) |
---|
600 | /* Convert a RGB image to a grayscale of the same width. This allows us, |
---|
601 | * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
---|
602 | */ |
---|
603 | |
---|
604 | void PNGAPI |
---|
605 | png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, |
---|
606 | double green) |
---|
607 | { |
---|
608 | int red_fixed = (int)((float)red*100000.0 + 0.5); |
---|
609 | int green_fixed = (int)((float)green*100000.0 + 0.5); |
---|
610 | png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed); |
---|
611 | } |
---|
612 | #endif |
---|
613 | |
---|
614 | void PNGAPI |
---|
615 | png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, |
---|
616 | png_fixed_point red, png_fixed_point green) |
---|
617 | { |
---|
618 | png_debug(1, "in png_set_rgb_to_gray\n"); |
---|
619 | switch(error_action) |
---|
620 | { |
---|
621 | case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY; |
---|
622 | break; |
---|
623 | case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
---|
624 | break; |
---|
625 | case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
---|
626 | } |
---|
627 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
628 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
---|
629 | png_ptr->transformations |= PNG_EXPAND; |
---|
630 | #else |
---|
631 | { |
---|
632 | png_warning(png_ptr, "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED."); |
---|
633 | png_ptr->transformations &= ~PNG_RGB_TO_GRAY; |
---|
634 | } |
---|
635 | #endif |
---|
636 | { |
---|
637 | png_uint_16 red_int, green_int; |
---|
638 | if(red < 0 || green < 0) |
---|
639 | { |
---|
640 | red_int = 6968; /* .212671 * 32768 + .5 */ |
---|
641 | green_int = 23434; /* .715160 * 32768 + .5 */ |
---|
642 | } |
---|
643 | else if(red + green < 100000L) |
---|
644 | { |
---|
645 | red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); |
---|
646 | green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); |
---|
647 | } |
---|
648 | else |
---|
649 | { |
---|
650 | png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); |
---|
651 | red_int = 6968; |
---|
652 | green_int = 23434; |
---|
653 | } |
---|
654 | png_ptr->rgb_to_gray_red_coeff = red_int; |
---|
655 | png_ptr->rgb_to_gray_green_coeff = green_int; |
---|
656 | png_ptr->rgb_to_gray_blue_coeff = (png_uint_16)(32768-red_int-green_int); |
---|
657 | } |
---|
658 | } |
---|
659 | #endif |
---|
660 | |
---|
661 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ |
---|
662 | defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \ |
---|
663 | defined(PNG_LEGACY_SUPPORTED) |
---|
664 | void PNGAPI |
---|
665 | png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr |
---|
666 | read_user_transform_fn) |
---|
667 | { |
---|
668 | png_debug(1, "in png_set_read_user_transform_fn\n"); |
---|
669 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
---|
670 | png_ptr->transformations |= PNG_USER_TRANSFORM; |
---|
671 | png_ptr->read_user_transform_fn = read_user_transform_fn; |
---|
672 | #endif |
---|
673 | #ifdef PNG_LEGACY_SUPPORTED |
---|
674 | if(read_user_transform_fn) |
---|
675 | png_warning(png_ptr, |
---|
676 | "This version of libpng does not support user transforms"); |
---|
677 | #endif |
---|
678 | } |
---|
679 | #endif |
---|
680 | |
---|
681 | /* Initialize everything needed for the read. This includes modifying |
---|
682 | * the palette. |
---|
683 | */ |
---|
684 | void /* PRIVATE */ |
---|
685 | png_init_read_transformations(png_structp png_ptr) |
---|
686 | { |
---|
687 | png_debug(1, "in png_init_read_transformations\n"); |
---|
688 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
689 | if(png_ptr != NULL) |
---|
690 | #endif |
---|
691 | { |
---|
692 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \ |
---|
693 | || defined(PNG_READ_GAMMA_SUPPORTED) |
---|
694 | int color_type = png_ptr->color_type; |
---|
695 | #endif |
---|
696 | |
---|
697 | #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
698 | if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
---|
699 | (png_ptr->transformations & PNG_EXPAND)) |
---|
700 | { |
---|
701 | if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ |
---|
702 | { |
---|
703 | /* expand background chunk. */ |
---|
704 | switch (png_ptr->bit_depth) |
---|
705 | { |
---|
706 | case 1: |
---|
707 | png_ptr->background.gray *= (png_uint_16)0xff; |
---|
708 | png_ptr->background.red = png_ptr->background.green |
---|
709 | = png_ptr->background.blue = png_ptr->background.gray; |
---|
710 | break; |
---|
711 | case 2: |
---|
712 | png_ptr->background.gray *= (png_uint_16)0x55; |
---|
713 | png_ptr->background.red = png_ptr->background.green |
---|
714 | = png_ptr->background.blue = png_ptr->background.gray; |
---|
715 | break; |
---|
716 | case 4: |
---|
717 | png_ptr->background.gray *= (png_uint_16)0x11; |
---|
718 | png_ptr->background.red = png_ptr->background.green |
---|
719 | = png_ptr->background.blue = png_ptr->background.gray; |
---|
720 | break; |
---|
721 | case 8: |
---|
722 | case 16: |
---|
723 | png_ptr->background.red = png_ptr->background.green |
---|
724 | = png_ptr->background.blue = png_ptr->background.gray; |
---|
725 | break; |
---|
726 | } |
---|
727 | } |
---|
728 | else if (color_type == PNG_COLOR_TYPE_PALETTE) |
---|
729 | { |
---|
730 | png_ptr->background.red = |
---|
731 | png_ptr->palette[png_ptr->background.index].red; |
---|
732 | png_ptr->background.green = |
---|
733 | png_ptr->palette[png_ptr->background.index].green; |
---|
734 | png_ptr->background.blue = |
---|
735 | png_ptr->palette[png_ptr->background.index].blue; |
---|
736 | |
---|
737 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
---|
738 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
---|
739 | { |
---|
740 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
---|
741 | if (!(png_ptr->transformations & PNG_EXPAND)) |
---|
742 | #endif |
---|
743 | { |
---|
744 | /* invert the alpha channel (in tRNS) unless the pixels are |
---|
745 | going to be expanded, in which case leave it for later */ |
---|
746 | int i,istop; |
---|
747 | istop=(int)png_ptr->num_trans; |
---|
748 | for (i=0; i<istop; i++) |
---|
749 | png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]); |
---|
750 | } |
---|
751 | } |
---|
752 | #endif |
---|
753 | |
---|
754 | } |
---|
755 | } |
---|
756 | #endif |
---|
757 | |
---|
758 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) |
---|
759 | png_ptr->background_1 = png_ptr->background; |
---|
760 | #endif |
---|
761 | #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
---|
762 | |
---|
763 | if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0) |
---|
764 | && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0) |
---|
765 | < PNG_GAMMA_THRESHOLD)) |
---|
766 | { |
---|
767 | int i,k; |
---|
768 | k=0; |
---|
769 | for (i=0; i<png_ptr->num_trans; i++) |
---|
770 | { |
---|
771 | if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff) |
---|
772 | k=1; /* partial transparency is present */ |
---|
773 | } |
---|
774 | if (k == 0) |
---|
775 | png_ptr->transformations &= (~PNG_GAMMA); |
---|
776 | } |
---|
777 | |
---|
778 | if (png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) |
---|
779 | { |
---|
780 | png_build_gamma_table(png_ptr); |
---|
781 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
782 | if (png_ptr->transformations & PNG_BACKGROUND) |
---|
783 | { |
---|
784 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
---|
785 | { |
---|
786 | /* could skip if no transparency and |
---|
787 | */ |
---|
788 | png_color back, back_1; |
---|
789 | png_colorp palette = png_ptr->palette; |
---|
790 | int num_palette = png_ptr->num_palette; |
---|
791 | int i; |
---|
792 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
---|
793 | { |
---|
794 | back.red = png_ptr->gamma_table[png_ptr->background.red]; |
---|
795 | back.green = png_ptr->gamma_table[png_ptr->background.green]; |
---|
796 | back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
---|
797 | |
---|
798 | back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
---|
799 | back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
---|
800 | back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
---|
801 | } |
---|
802 | else |
---|
803 | { |
---|
804 | double g, gs; |
---|
805 | |
---|
806 | switch (png_ptr->background_gamma_type) |
---|
807 | { |
---|
808 | case PNG_BACKGROUND_GAMMA_SCREEN: |
---|
809 | g = (png_ptr->screen_gamma); |
---|
810 | gs = 1.0; |
---|
811 | break; |
---|
812 | case PNG_BACKGROUND_GAMMA_FILE: |
---|
813 | g = 1.0 / (png_ptr->gamma); |
---|
814 | gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
---|
815 | break; |
---|
816 | case PNG_BACKGROUND_GAMMA_UNIQUE: |
---|
817 | g = 1.0 / (png_ptr->background_gamma); |
---|
818 | gs = 1.0 / (png_ptr->background_gamma * |
---|
819 | png_ptr->screen_gamma); |
---|
820 | break; |
---|
821 | default: |
---|
822 | g = 1.0; /* back_1 */ |
---|
823 | gs = 1.0; /* back */ |
---|
824 | } |
---|
825 | |
---|
826 | if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) |
---|
827 | { |
---|
828 | back.red = (png_byte)png_ptr->background.red; |
---|
829 | back.green = (png_byte)png_ptr->background.green; |
---|
830 | back.blue = (png_byte)png_ptr->background.blue; |
---|
831 | } |
---|
832 | else |
---|
833 | { |
---|
834 | back.red = (png_byte)(pow( |
---|
835 | (double)png_ptr->background.red/255, gs) * 255.0 + .5); |
---|
836 | back.green = (png_byte)(pow( |
---|
837 | (double)png_ptr->background.green/255, gs) * 255.0 + .5); |
---|
838 | back.blue = (png_byte)(pow( |
---|
839 | (double)png_ptr->background.blue/255, gs) * 255.0 + .5); |
---|
840 | } |
---|
841 | |
---|
842 | back_1.red = (png_byte)(pow( |
---|
843 | (double)png_ptr->background.red/255, g) * 255.0 + .5); |
---|
844 | back_1.green = (png_byte)(pow( |
---|
845 | (double)png_ptr->background.green/255, g) * 255.0 + .5); |
---|
846 | back_1.blue = (png_byte)(pow( |
---|
847 | (double)png_ptr->background.blue/255, g) * 255.0 + .5); |
---|
848 | } |
---|
849 | for (i = 0; i < num_palette; i++) |
---|
850 | { |
---|
851 | if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
---|
852 | { |
---|
853 | if (png_ptr->trans[i] == 0) |
---|
854 | { |
---|
855 | palette[i] = back; |
---|
856 | } |
---|
857 | else /* if (png_ptr->trans[i] != 0xff) */ |
---|
858 | { |
---|
859 | png_byte v, w; |
---|
860 | |
---|
861 | v = png_ptr->gamma_to_1[palette[i].red]; |
---|
862 | png_composite(w, v, png_ptr->trans[i], back_1.red); |
---|
863 | palette[i].red = png_ptr->gamma_from_1[w]; |
---|
864 | |
---|
865 | v = png_ptr->gamma_to_1[palette[i].green]; |
---|
866 | png_composite(w, v, png_ptr->trans[i], back_1.green); |
---|
867 | palette[i].green = png_ptr->gamma_from_1[w]; |
---|
868 | |
---|
869 | v = png_ptr->gamma_to_1[palette[i].blue]; |
---|
870 | png_composite(w, v, png_ptr->trans[i], back_1.blue); |
---|
871 | palette[i].blue = png_ptr->gamma_from_1[w]; |
---|
872 | } |
---|
873 | } |
---|
874 | else |
---|
875 | { |
---|
876 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
---|
877 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
---|
878 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
---|
879 | } |
---|
880 | } |
---|
881 | } |
---|
882 | /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ |
---|
883 | else |
---|
884 | /* color_type != PNG_COLOR_TYPE_PALETTE */ |
---|
885 | { |
---|
886 | double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); |
---|
887 | double g = 1.0; |
---|
888 | double gs = 1.0; |
---|
889 | |
---|
890 | switch (png_ptr->background_gamma_type) |
---|
891 | { |
---|
892 | case PNG_BACKGROUND_GAMMA_SCREEN: |
---|
893 | g = (png_ptr->screen_gamma); |
---|
894 | gs = 1.0; |
---|
895 | break; |
---|
896 | case PNG_BACKGROUND_GAMMA_FILE: |
---|
897 | g = 1.0 / (png_ptr->gamma); |
---|
898 | gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
---|
899 | break; |
---|
900 | case PNG_BACKGROUND_GAMMA_UNIQUE: |
---|
901 | g = 1.0 / (png_ptr->background_gamma); |
---|
902 | gs = 1.0 / (png_ptr->background_gamma * |
---|
903 | png_ptr->screen_gamma); |
---|
904 | break; |
---|
905 | } |
---|
906 | |
---|
907 | png_ptr->background_1.gray = (png_uint_16)(pow( |
---|
908 | (double)png_ptr->background.gray / m, g) * m + .5); |
---|
909 | png_ptr->background.gray = (png_uint_16)(pow( |
---|
910 | (double)png_ptr->background.gray / m, gs) * m + .5); |
---|
911 | |
---|
912 | if ((png_ptr->background.red != png_ptr->background.green) || |
---|
913 | (png_ptr->background.red != png_ptr->background.blue) || |
---|
914 | (png_ptr->background.red != png_ptr->background.gray)) |
---|
915 | { |
---|
916 | /* RGB or RGBA with color background */ |
---|
917 | png_ptr->background_1.red = (png_uint_16)(pow( |
---|
918 | (double)png_ptr->background.red / m, g) * m + .5); |
---|
919 | png_ptr->background_1.green = (png_uint_16)(pow( |
---|
920 | (double)png_ptr->background.green / m, g) * m + .5); |
---|
921 | png_ptr->background_1.blue = (png_uint_16)(pow( |
---|
922 | (double)png_ptr->background.blue / m, g) * m + .5); |
---|
923 | png_ptr->background.red = (png_uint_16)(pow( |
---|
924 | (double)png_ptr->background.red / m, gs) * m + .5); |
---|
925 | png_ptr->background.green = (png_uint_16)(pow( |
---|
926 | (double)png_ptr->background.green / m, gs) * m + .5); |
---|
927 | png_ptr->background.blue = (png_uint_16)(pow( |
---|
928 | (double)png_ptr->background.blue / m, gs) * m + .5); |
---|
929 | } |
---|
930 | else |
---|
931 | { |
---|
932 | /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ |
---|
933 | png_ptr->background_1.red = png_ptr->background_1.green |
---|
934 | = png_ptr->background_1.blue = png_ptr->background_1.gray; |
---|
935 | png_ptr->background.red = png_ptr->background.green |
---|
936 | = png_ptr->background.blue = png_ptr->background.gray; |
---|
937 | } |
---|
938 | } |
---|
939 | } |
---|
940 | else |
---|
941 | /* transformation does not include PNG_BACKGROUND */ |
---|
942 | #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
---|
943 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
---|
944 | { |
---|
945 | png_colorp palette = png_ptr->palette; |
---|
946 | int num_palette = png_ptr->num_palette; |
---|
947 | int i; |
---|
948 | |
---|
949 | for (i = 0; i < num_palette; i++) |
---|
950 | { |
---|
951 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
---|
952 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
---|
953 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
---|
954 | } |
---|
955 | } |
---|
956 | } |
---|
957 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
958 | else |
---|
959 | #endif |
---|
960 | #endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */ |
---|
961 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
962 | /* No GAMMA transformation */ |
---|
963 | if ((png_ptr->transformations & PNG_BACKGROUND) && |
---|
964 | (color_type == PNG_COLOR_TYPE_PALETTE)) |
---|
965 | { |
---|
966 | int i; |
---|
967 | int istop = (int)png_ptr->num_trans; |
---|
968 | png_color back; |
---|
969 | png_colorp palette = png_ptr->palette; |
---|
970 | |
---|
971 | back.red = (png_byte)png_ptr->background.red; |
---|
972 | back.green = (png_byte)png_ptr->background.green; |
---|
973 | back.blue = (png_byte)png_ptr->background.blue; |
---|
974 | |
---|
975 | for (i = 0; i < istop; i++) |
---|
976 | { |
---|
977 | if (png_ptr->trans[i] == 0) |
---|
978 | { |
---|
979 | palette[i] = back; |
---|
980 | } |
---|
981 | else if (png_ptr->trans[i] != 0xff) |
---|
982 | { |
---|
983 | /* The png_composite() macro is defined in png.h */ |
---|
984 | png_composite(palette[i].red, palette[i].red, |
---|
985 | png_ptr->trans[i], back.red); |
---|
986 | png_composite(palette[i].green, palette[i].green, |
---|
987 | png_ptr->trans[i], back.green); |
---|
988 | png_composite(palette[i].blue, palette[i].blue, |
---|
989 | png_ptr->trans[i], back.blue); |
---|
990 | } |
---|
991 | } |
---|
992 | } |
---|
993 | #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
---|
994 | |
---|
995 | #if defined(PNG_READ_SHIFT_SUPPORTED) |
---|
996 | if ((png_ptr->transformations & PNG_SHIFT) && |
---|
997 | (color_type == PNG_COLOR_TYPE_PALETTE)) |
---|
998 | { |
---|
999 | png_uint_16 i; |
---|
1000 | png_uint_16 istop = png_ptr->num_palette; |
---|
1001 | int sr = 8 - png_ptr->sig_bit.red; |
---|
1002 | int sg = 8 - png_ptr->sig_bit.green; |
---|
1003 | int sb = 8 - png_ptr->sig_bit.blue; |
---|
1004 | |
---|
1005 | if (sr < 0 || sr > 8) |
---|
1006 | sr = 0; |
---|
1007 | if (sg < 0 || sg > 8) |
---|
1008 | sg = 0; |
---|
1009 | if (sb < 0 || sb > 8) |
---|
1010 | sb = 0; |
---|
1011 | for (i = 0; i < istop; i++) |
---|
1012 | { |
---|
1013 | png_ptr->palette[i].red >>= sr; |
---|
1014 | png_ptr->palette[i].green >>= sg; |
---|
1015 | png_ptr->palette[i].blue >>= sb; |
---|
1016 | } |
---|
1017 | } |
---|
1018 | #endif /* PNG_READ_SHIFT_SUPPORTED */ |
---|
1019 | } |
---|
1020 | #if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \ |
---|
1021 | && !defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
1022 | if(png_ptr) |
---|
1023 | return; |
---|
1024 | #endif |
---|
1025 | } |
---|
1026 | |
---|
1027 | /* Modify the info structure to reflect the transformations. The |
---|
1028 | * info should be updated so a PNG file could be written with it, |
---|
1029 | * assuming the transformations result in valid PNG data. |
---|
1030 | */ |
---|
1031 | void /* PRIVATE */ |
---|
1032 | png_read_transform_info(png_structp png_ptr, png_infop info_ptr) |
---|
1033 | { |
---|
1034 | png_debug(1, "in png_read_transform_info\n"); |
---|
1035 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
---|
1036 | if (png_ptr->transformations & PNG_EXPAND) |
---|
1037 | { |
---|
1038 | if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
1039 | { |
---|
1040 | if (png_ptr->num_trans) |
---|
1041 | info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
---|
1042 | else |
---|
1043 | info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
---|
1044 | info_ptr->bit_depth = 8; |
---|
1045 | info_ptr->num_trans = 0; |
---|
1046 | } |
---|
1047 | else |
---|
1048 | { |
---|
1049 | if (png_ptr->num_trans) |
---|
1050 | info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
---|
1051 | if (info_ptr->bit_depth < 8) |
---|
1052 | info_ptr->bit_depth = 8; |
---|
1053 | info_ptr->num_trans = 0; |
---|
1054 | } |
---|
1055 | } |
---|
1056 | #endif |
---|
1057 | |
---|
1058 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
1059 | if (png_ptr->transformations & PNG_BACKGROUND) |
---|
1060 | { |
---|
1061 | info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
---|
1062 | info_ptr->num_trans = 0; |
---|
1063 | info_ptr->background = png_ptr->background; |
---|
1064 | } |
---|
1065 | #endif |
---|
1066 | |
---|
1067 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
1068 | if (png_ptr->transformations & PNG_GAMMA) |
---|
1069 | { |
---|
1070 | #ifdef PNG_FLOATING_POINT_SUPPORTED |
---|
1071 | info_ptr->gamma = png_ptr->gamma; |
---|
1072 | #endif |
---|
1073 | #ifdef PNG_FIXED_POINT_SUPPORTED |
---|
1074 | info_ptr->int_gamma = png_ptr->int_gamma; |
---|
1075 | #endif |
---|
1076 | } |
---|
1077 | #endif |
---|
1078 | |
---|
1079 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
---|
1080 | if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16)) |
---|
1081 | info_ptr->bit_depth = 8; |
---|
1082 | #endif |
---|
1083 | |
---|
1084 | #if defined(PNG_READ_DITHER_SUPPORTED) |
---|
1085 | if (png_ptr->transformations & PNG_DITHER) |
---|
1086 | { |
---|
1087 | if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
---|
1088 | (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
---|
1089 | png_ptr->palette_lookup && info_ptr->bit_depth == 8) |
---|
1090 | { |
---|
1091 | info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
---|
1092 | } |
---|
1093 | } |
---|
1094 | #endif |
---|
1095 | |
---|
1096 | #if defined(PNG_READ_PACK_SUPPORTED) |
---|
1097 | if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) |
---|
1098 | info_ptr->bit_depth = 8; |
---|
1099 | #endif |
---|
1100 | |
---|
1101 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
---|
1102 | if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
---|
1103 | info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
---|
1104 | #endif |
---|
1105 | |
---|
1106 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
---|
1107 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
---|
1108 | info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; |
---|
1109 | #endif |
---|
1110 | |
---|
1111 | if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
1112 | info_ptr->channels = 1; |
---|
1113 | else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) |
---|
1114 | info_ptr->channels = 3; |
---|
1115 | else |
---|
1116 | info_ptr->channels = 1; |
---|
1117 | |
---|
1118 | #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
---|
1119 | if (png_ptr->transformations & PNG_STRIP_ALPHA) |
---|
1120 | info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
---|
1121 | #endif |
---|
1122 | |
---|
1123 | if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
---|
1124 | info_ptr->channels++; |
---|
1125 | |
---|
1126 | #if defined(PNG_READ_FILLER_SUPPORTED) |
---|
1127 | /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ |
---|
1128 | if ((png_ptr->transformations & PNG_FILLER) && |
---|
1129 | ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
---|
1130 | (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) |
---|
1131 | { |
---|
1132 | info_ptr->channels++; |
---|
1133 | #if 0 /* if adding a true alpha channel not just filler */ |
---|
1134 | info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
---|
1135 | #endif |
---|
1136 | } |
---|
1137 | #endif |
---|
1138 | |
---|
1139 | #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ |
---|
1140 | defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
---|
1141 | if(png_ptr->transformations & PNG_USER_TRANSFORM) |
---|
1142 | { |
---|
1143 | if(info_ptr->bit_depth < png_ptr->user_transform_depth) |
---|
1144 | info_ptr->bit_depth = png_ptr->user_transform_depth; |
---|
1145 | if(info_ptr->channels < png_ptr->user_transform_channels) |
---|
1146 | info_ptr->channels = png_ptr->user_transform_channels; |
---|
1147 | } |
---|
1148 | #endif |
---|
1149 | |
---|
1150 | info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
---|
1151 | info_ptr->bit_depth); |
---|
1152 | info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3); |
---|
1153 | |
---|
1154 | #if !defined(PNG_READ_EXPAND_SUPPORTED) |
---|
1155 | if(png_ptr) |
---|
1156 | return; |
---|
1157 | #endif |
---|
1158 | } |
---|
1159 | |
---|
1160 | /* Transform the row. The order of transformations is significant, |
---|
1161 | * and is very touchy. If you add a transformation, take care to |
---|
1162 | * decide how it fits in with the other transformations here. |
---|
1163 | */ |
---|
1164 | void /* PRIVATE */ |
---|
1165 | png_do_read_transformations(png_structp png_ptr) |
---|
1166 | { |
---|
1167 | png_debug(1, "in png_do_read_transformations\n"); |
---|
1168 | #if !defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1169 | if (png_ptr->row_buf == NULL) |
---|
1170 | { |
---|
1171 | #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) |
---|
1172 | char msg[50]; |
---|
1173 | |
---|
1174 | sprintf(msg, "NULL row buffer for row %ld, pass %d", png_ptr->row_number, |
---|
1175 | png_ptr->pass); |
---|
1176 | png_error(png_ptr, msg); |
---|
1177 | #else |
---|
1178 | png_error(png_ptr, "NULL row buffer"); |
---|
1179 | #endif |
---|
1180 | } |
---|
1181 | #endif |
---|
1182 | |
---|
1183 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
---|
1184 | if (png_ptr->transformations & PNG_EXPAND) |
---|
1185 | { |
---|
1186 | if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) |
---|
1187 | { |
---|
1188 | png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1189 | png_ptr->palette, png_ptr->trans, png_ptr->num_trans); |
---|
1190 | } |
---|
1191 | else |
---|
1192 | { |
---|
1193 | if (png_ptr->num_trans) |
---|
1194 | png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1195 | &(png_ptr->trans_values)); |
---|
1196 | else |
---|
1197 | png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1198 | NULL); |
---|
1199 | } |
---|
1200 | } |
---|
1201 | #endif |
---|
1202 | |
---|
1203 | #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
---|
1204 | if (png_ptr->transformations & PNG_STRIP_ALPHA) |
---|
1205 | png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1206 | PNG_FLAG_FILLER_AFTER); |
---|
1207 | #endif |
---|
1208 | |
---|
1209 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
---|
1210 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
---|
1211 | { |
---|
1212 | int rgb_error = |
---|
1213 | png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1214 | if(rgb_error) |
---|
1215 | { |
---|
1216 | png_ptr->rgb_to_gray_status=1; |
---|
1217 | if(png_ptr->transformations == PNG_RGB_TO_GRAY_WARN) |
---|
1218 | png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
---|
1219 | if(png_ptr->transformations == PNG_RGB_TO_GRAY_ERR) |
---|
1220 | png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
---|
1221 | } |
---|
1222 | } |
---|
1223 | #endif |
---|
1224 | |
---|
1225 | /* |
---|
1226 | From Andreas Dilger e-mail to png-implement, 26 March 1998: |
---|
1227 | |
---|
1228 | In most cases, the "simple transparency" should be done prior to doing |
---|
1229 | gray-to-RGB, or you will have to test 3x as many bytes to check if a |
---|
1230 | pixel is transparent. You would also need to make sure that the |
---|
1231 | transparency information is upgraded to RGB. |
---|
1232 | |
---|
1233 | To summarize, the current flow is: |
---|
1234 | - Gray + simple transparency -> compare 1 or 2 gray bytes and composite |
---|
1235 | with background "in place" if transparent, |
---|
1236 | convert to RGB if necessary |
---|
1237 | - Gray + alpha -> composite with gray background and remove alpha bytes, |
---|
1238 | convert to RGB if necessary |
---|
1239 | |
---|
1240 | To support RGB backgrounds for gray images we need: |
---|
1241 | - Gray + simple transparency -> convert to RGB + simple transparency, compare |
---|
1242 | 3 or 6 bytes and composite with background |
---|
1243 | "in place" if transparent (3x compare/pixel |
---|
1244 | compared to doing composite with gray bkgrnd) |
---|
1245 | - Gray + alpha -> convert to RGB + alpha, composite with background and |
---|
1246 | remove alpha bytes (3x float operations/pixel |
---|
1247 | compared with composite on gray background) |
---|
1248 | |
---|
1249 | Greg's change will do this. The reason it wasn't done before is for |
---|
1250 | performance, as this increases the per-pixel operations. If we would check |
---|
1251 | in advance if the background was gray or RGB, and position the gray-to-RGB |
---|
1252 | transform appropriately, then it would save a lot of work/time. |
---|
1253 | */ |
---|
1254 | |
---|
1255 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
---|
1256 | /* if gray -> RGB, do so now only if background is non-gray; else do later |
---|
1257 | * for performance reasons */ |
---|
1258 | if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
---|
1259 | !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
---|
1260 | png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1261 | #endif |
---|
1262 | |
---|
1263 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
1264 | if ((png_ptr->transformations & PNG_BACKGROUND) && |
---|
1265 | ((png_ptr->num_trans != 0 ) || |
---|
1266 | (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) |
---|
1267 | png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1268 | &(png_ptr->trans_values), &(png_ptr->background) |
---|
1269 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
1270 | , &(png_ptr->background_1), |
---|
1271 | png_ptr->gamma_table, png_ptr->gamma_from_1, |
---|
1272 | png_ptr->gamma_to_1, png_ptr->gamma_16_table, |
---|
1273 | png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, |
---|
1274 | png_ptr->gamma_shift |
---|
1275 | #endif |
---|
1276 | ); |
---|
1277 | #endif |
---|
1278 | |
---|
1279 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
1280 | if ((png_ptr->transformations & PNG_GAMMA) && |
---|
1281 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
1282 | !((png_ptr->transformations & PNG_BACKGROUND) && |
---|
1283 | ((png_ptr->num_trans != 0) || |
---|
1284 | (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && |
---|
1285 | #endif |
---|
1286 | (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) |
---|
1287 | png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1288 | png_ptr->gamma_table, png_ptr->gamma_16_table, |
---|
1289 | png_ptr->gamma_shift); |
---|
1290 | #endif |
---|
1291 | |
---|
1292 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
---|
1293 | if (png_ptr->transformations & PNG_16_TO_8) |
---|
1294 | png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1295 | #endif |
---|
1296 | |
---|
1297 | #if defined(PNG_READ_DITHER_SUPPORTED) |
---|
1298 | if (png_ptr->transformations & PNG_DITHER) |
---|
1299 | { |
---|
1300 | png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1301 | png_ptr->palette_lookup, png_ptr->dither_index); |
---|
1302 | if(png_ptr->row_info.rowbytes == (png_uint_32)0) |
---|
1303 | png_error(png_ptr, "png_do_dither returned rowbytes=0"); |
---|
1304 | } |
---|
1305 | #endif |
---|
1306 | |
---|
1307 | #if defined(PNG_READ_INVERT_SUPPORTED) |
---|
1308 | if (png_ptr->transformations & PNG_INVERT_MONO) |
---|
1309 | png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1310 | #endif |
---|
1311 | |
---|
1312 | #if defined(PNG_READ_SHIFT_SUPPORTED) |
---|
1313 | if (png_ptr->transformations & PNG_SHIFT) |
---|
1314 | png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1315 | &(png_ptr->shift)); |
---|
1316 | #endif |
---|
1317 | |
---|
1318 | #if defined(PNG_READ_PACK_SUPPORTED) |
---|
1319 | if (png_ptr->transformations & PNG_PACK) |
---|
1320 | png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1321 | #endif |
---|
1322 | |
---|
1323 | #if defined(PNG_READ_BGR_SUPPORTED) |
---|
1324 | if (png_ptr->transformations & PNG_BGR) |
---|
1325 | png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1326 | #endif |
---|
1327 | |
---|
1328 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
---|
1329 | if (png_ptr->transformations & PNG_PACKSWAP) |
---|
1330 | png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1331 | #endif |
---|
1332 | |
---|
1333 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
---|
1334 | /* if gray -> RGB, do so now only if we did not do so above */ |
---|
1335 | if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
---|
1336 | (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
---|
1337 | png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1338 | #endif |
---|
1339 | |
---|
1340 | #if defined(PNG_READ_FILLER_SUPPORTED) |
---|
1341 | if (png_ptr->transformations & PNG_FILLER) |
---|
1342 | png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
---|
1343 | (png_uint_32)png_ptr->filler, png_ptr->flags); |
---|
1344 | #endif |
---|
1345 | |
---|
1346 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
---|
1347 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
---|
1348 | png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1349 | #endif |
---|
1350 | |
---|
1351 | #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
---|
1352 | if (png_ptr->transformations & PNG_SWAP_ALPHA) |
---|
1353 | png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1354 | #endif |
---|
1355 | |
---|
1356 | #if defined(PNG_READ_SWAP_SUPPORTED) |
---|
1357 | if (png_ptr->transformations & PNG_SWAP_BYTES) |
---|
1358 | png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
---|
1359 | #endif |
---|
1360 | |
---|
1361 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
---|
1362 | if (png_ptr->transformations & PNG_USER_TRANSFORM) |
---|
1363 | { |
---|
1364 | if(png_ptr->read_user_transform_fn != NULL) |
---|
1365 | (*(png_ptr->read_user_transform_fn)) /* user read transform function */ |
---|
1366 | (png_ptr, /* png_ptr */ |
---|
1367 | &(png_ptr->row_info), /* row_info: */ |
---|
1368 | /* png_uint_32 width; width of row */ |
---|
1369 | /* png_uint_32 rowbytes; number of bytes in row */ |
---|
1370 | /* png_byte color_type; color type of pixels */ |
---|
1371 | /* png_byte bit_depth; bit depth of samples */ |
---|
1372 | /* png_byte channels; number of channels (1-4) */ |
---|
1373 | /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
---|
1374 | png_ptr->row_buf + 1); /* start of pixel data for row */ |
---|
1375 | #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) |
---|
1376 | if(png_ptr->user_transform_depth) |
---|
1377 | png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; |
---|
1378 | if(png_ptr->user_transform_channels) |
---|
1379 | png_ptr->row_info.channels = png_ptr->user_transform_channels; |
---|
1380 | #endif |
---|
1381 | png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * |
---|
1382 | png_ptr->row_info.channels); |
---|
1383 | png_ptr->row_info.rowbytes = (png_ptr->row_info.width * |
---|
1384 | png_ptr->row_info.pixel_depth+7)>>3; |
---|
1385 | } |
---|
1386 | #endif |
---|
1387 | |
---|
1388 | } |
---|
1389 | |
---|
1390 | #if defined(PNG_READ_PACK_SUPPORTED) |
---|
1391 | /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
---|
1392 | * without changing the actual values. Thus, if you had a row with |
---|
1393 | * a bit depth of 1, you would end up with bytes that only contained |
---|
1394 | * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
---|
1395 | * png_do_shift() after this. |
---|
1396 | */ |
---|
1397 | void /* PRIVATE */ |
---|
1398 | png_do_unpack(png_row_infop row_info, png_bytep row) |
---|
1399 | { |
---|
1400 | png_debug(1, "in png_do_unpack\n"); |
---|
1401 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1402 | if (row != NULL && row_info != NULL && row_info->bit_depth < 8) |
---|
1403 | #else |
---|
1404 | if (row_info->bit_depth < 8) |
---|
1405 | #endif |
---|
1406 | { |
---|
1407 | png_uint_32 i; |
---|
1408 | png_uint_32 row_width=row_info->width; |
---|
1409 | |
---|
1410 | switch (row_info->bit_depth) |
---|
1411 | { |
---|
1412 | case 1: |
---|
1413 | { |
---|
1414 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); |
---|
1415 | png_bytep dp = row + (png_size_t)row_width - 1; |
---|
1416 | png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); |
---|
1417 | for (i = 0; i < row_width; i++) |
---|
1418 | { |
---|
1419 | *dp = (png_byte)((*sp >> shift) & 0x01); |
---|
1420 | if (shift == 7) |
---|
1421 | { |
---|
1422 | shift = 0; |
---|
1423 | sp--; |
---|
1424 | } |
---|
1425 | else |
---|
1426 | shift++; |
---|
1427 | |
---|
1428 | dp--; |
---|
1429 | } |
---|
1430 | break; |
---|
1431 | } |
---|
1432 | case 2: |
---|
1433 | { |
---|
1434 | |
---|
1435 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); |
---|
1436 | png_bytep dp = row + (png_size_t)row_width - 1; |
---|
1437 | png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
---|
1438 | for (i = 0; i < row_width; i++) |
---|
1439 | { |
---|
1440 | *dp = (png_byte)((*sp >> shift) & 0x03); |
---|
1441 | if (shift == 6) |
---|
1442 | { |
---|
1443 | shift = 0; |
---|
1444 | sp--; |
---|
1445 | } |
---|
1446 | else |
---|
1447 | shift += 2; |
---|
1448 | |
---|
1449 | dp--; |
---|
1450 | } |
---|
1451 | break; |
---|
1452 | } |
---|
1453 | case 4: |
---|
1454 | { |
---|
1455 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); |
---|
1456 | png_bytep dp = row + (png_size_t)row_width - 1; |
---|
1457 | png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
---|
1458 | for (i = 0; i < row_width; i++) |
---|
1459 | { |
---|
1460 | *dp = (png_byte)((*sp >> shift) & 0x0f); |
---|
1461 | if (shift == 4) |
---|
1462 | { |
---|
1463 | shift = 0; |
---|
1464 | sp--; |
---|
1465 | } |
---|
1466 | else |
---|
1467 | shift = 4; |
---|
1468 | |
---|
1469 | dp--; |
---|
1470 | } |
---|
1471 | break; |
---|
1472 | } |
---|
1473 | } |
---|
1474 | row_info->bit_depth = 8; |
---|
1475 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
---|
1476 | row_info->rowbytes = row_width * row_info->channels; |
---|
1477 | } |
---|
1478 | } |
---|
1479 | #endif |
---|
1480 | |
---|
1481 | #if defined(PNG_READ_SHIFT_SUPPORTED) |
---|
1482 | /* Reverse the effects of png_do_shift. This routine merely shifts the |
---|
1483 | * pixels back to their significant bits values. Thus, if you have |
---|
1484 | * a row of bit depth 8, but only 5 are significant, this will shift |
---|
1485 | * the values back to 0 through 31. |
---|
1486 | */ |
---|
1487 | void /* PRIVATE */ |
---|
1488 | png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) |
---|
1489 | { |
---|
1490 | png_debug(1, "in png_do_unshift\n"); |
---|
1491 | if ( |
---|
1492 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1493 | row != NULL && row_info != NULL && sig_bits != NULL && |
---|
1494 | #endif |
---|
1495 | row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
---|
1496 | { |
---|
1497 | int shift[4]; |
---|
1498 | int channels = 0; |
---|
1499 | int c; |
---|
1500 | png_uint_16 value = 0; |
---|
1501 | png_uint_32 row_width = row_info->width; |
---|
1502 | |
---|
1503 | if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
---|
1504 | { |
---|
1505 | shift[channels++] = row_info->bit_depth - sig_bits->red; |
---|
1506 | shift[channels++] = row_info->bit_depth - sig_bits->green; |
---|
1507 | shift[channels++] = row_info->bit_depth - sig_bits->blue; |
---|
1508 | } |
---|
1509 | else |
---|
1510 | { |
---|
1511 | shift[channels++] = row_info->bit_depth - sig_bits->gray; |
---|
1512 | } |
---|
1513 | if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
---|
1514 | { |
---|
1515 | shift[channels++] = row_info->bit_depth - sig_bits->alpha; |
---|
1516 | } |
---|
1517 | |
---|
1518 | for (c = 0; c < channels; c++) |
---|
1519 | { |
---|
1520 | if (shift[c] <= 0) |
---|
1521 | shift[c] = 0; |
---|
1522 | else |
---|
1523 | value = 1; |
---|
1524 | } |
---|
1525 | |
---|
1526 | if (!value) |
---|
1527 | return; |
---|
1528 | |
---|
1529 | switch (row_info->bit_depth) |
---|
1530 | { |
---|
1531 | case 2: |
---|
1532 | { |
---|
1533 | png_bytep bp; |
---|
1534 | png_uint_32 i; |
---|
1535 | png_uint_32 istop = row_info->rowbytes; |
---|
1536 | |
---|
1537 | for (bp = row, i = 0; i < istop; i++) |
---|
1538 | { |
---|
1539 | *bp >>= 1; |
---|
1540 | *bp++ &= 0x55; |
---|
1541 | } |
---|
1542 | break; |
---|
1543 | } |
---|
1544 | case 4: |
---|
1545 | { |
---|
1546 | png_bytep bp = row; |
---|
1547 | png_uint_32 i; |
---|
1548 | png_uint_32 istop = row_info->rowbytes; |
---|
1549 | png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | |
---|
1550 | (png_byte)((int)0xf >> shift[0])); |
---|
1551 | |
---|
1552 | for (i = 0; i < istop; i++) |
---|
1553 | { |
---|
1554 | *bp >>= shift[0]; |
---|
1555 | *bp++ &= mask; |
---|
1556 | } |
---|
1557 | break; |
---|
1558 | } |
---|
1559 | case 8: |
---|
1560 | { |
---|
1561 | png_bytep bp = row; |
---|
1562 | png_uint_32 i; |
---|
1563 | png_uint_32 istop = row_width * channels; |
---|
1564 | |
---|
1565 | for (i = 0; i < istop; i++) |
---|
1566 | { |
---|
1567 | *bp++ >>= shift[i%channels]; |
---|
1568 | } |
---|
1569 | break; |
---|
1570 | } |
---|
1571 | case 16: |
---|
1572 | { |
---|
1573 | png_bytep bp = row; |
---|
1574 | png_uint_32 i; |
---|
1575 | png_uint_32 istop = channels * row_width; |
---|
1576 | |
---|
1577 | for (i = 0; i < istop; i++) |
---|
1578 | { |
---|
1579 | value = (png_uint_16)((*bp << 8) + *(bp + 1)); |
---|
1580 | value >>= shift[i%channels]; |
---|
1581 | *bp++ = (png_byte)(value >> 8); |
---|
1582 | *bp++ = (png_byte)(value & 0xff); |
---|
1583 | } |
---|
1584 | break; |
---|
1585 | } |
---|
1586 | } |
---|
1587 | } |
---|
1588 | } |
---|
1589 | #endif |
---|
1590 | |
---|
1591 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
---|
1592 | /* chop rows of bit depth 16 down to 8 */ |
---|
1593 | void /* PRIVATE */ |
---|
1594 | png_do_chop(png_row_infop row_info, png_bytep row) |
---|
1595 | { |
---|
1596 | png_debug(1, "in png_do_chop\n"); |
---|
1597 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1598 | if (row != NULL && row_info != NULL && row_info->bit_depth == 16) |
---|
1599 | #else |
---|
1600 | if (row_info->bit_depth == 16) |
---|
1601 | #endif |
---|
1602 | { |
---|
1603 | png_bytep sp = row; |
---|
1604 | png_bytep dp = row; |
---|
1605 | png_uint_32 i; |
---|
1606 | png_uint_32 istop = row_info->width * row_info->channels; |
---|
1607 | |
---|
1608 | for (i = 0; i<istop; i++, sp += 2, dp++) |
---|
1609 | { |
---|
1610 | #if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED) |
---|
1611 | /* This does a more accurate scaling of the 16-bit color |
---|
1612 | * value, rather than a simple low-byte truncation. |
---|
1613 | * |
---|
1614 | * What the ideal calculation should be: |
---|
1615 | * *dp = (((((png_uint_32)(*sp) << 8) | |
---|
1616 | * (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L; |
---|
1617 | * |
---|
1618 | * GRR: no, I think this is what it really should be: |
---|
1619 | * *dp = (((((png_uint_32)(*sp) << 8) | |
---|
1620 | * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L; |
---|
1621 | * |
---|
1622 | * GRR: here's the exact calculation with shifts: |
---|
1623 | * temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L; |
---|
1624 | * *dp = (temp - (temp >> 8)) >> 8; |
---|
1625 | * |
---|
1626 | * Approximate calculation with shift/add instead of multiply/divide: |
---|
1627 | * *dp = ((((png_uint_32)(*sp) << 8) | |
---|
1628 | * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; |
---|
1629 | * |
---|
1630 | * What we actually do to avoid extra shifting and conversion: |
---|
1631 | */ |
---|
1632 | |
---|
1633 | *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); |
---|
1634 | #else |
---|
1635 | /* Simply discard the low order byte */ |
---|
1636 | *dp = *sp; |
---|
1637 | #endif |
---|
1638 | } |
---|
1639 | row_info->bit_depth = 8; |
---|
1640 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
---|
1641 | row_info->rowbytes = row_info->width * row_info->channels; |
---|
1642 | } |
---|
1643 | } |
---|
1644 | #endif |
---|
1645 | |
---|
1646 | #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
---|
1647 | void /* PRIVATE */ |
---|
1648 | png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) |
---|
1649 | { |
---|
1650 | png_debug(1, "in png_do_read_swap_alpha\n"); |
---|
1651 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1652 | if (row != NULL && row_info != NULL) |
---|
1653 | #endif |
---|
1654 | { |
---|
1655 | png_uint_32 row_width = row_info->width; |
---|
1656 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
---|
1657 | { |
---|
1658 | /* This converts from RGBA to ARGB */ |
---|
1659 | if (row_info->bit_depth == 8) |
---|
1660 | { |
---|
1661 | png_bytep sp = row + row_info->rowbytes; |
---|
1662 | png_bytep dp = sp; |
---|
1663 | png_byte save; |
---|
1664 | png_uint_32 i; |
---|
1665 | |
---|
1666 | for (i = 0; i < row_width; i++) |
---|
1667 | { |
---|
1668 | save = *(--sp); |
---|
1669 | *(--dp) = *(--sp); |
---|
1670 | *(--dp) = *(--sp); |
---|
1671 | *(--dp) = *(--sp); |
---|
1672 | *(--dp) = save; |
---|
1673 | } |
---|
1674 | } |
---|
1675 | /* This converts from RRGGBBAA to AARRGGBB */ |
---|
1676 | else |
---|
1677 | { |
---|
1678 | png_bytep sp = row + row_info->rowbytes; |
---|
1679 | png_bytep dp = sp; |
---|
1680 | png_byte save[2]; |
---|
1681 | png_uint_32 i; |
---|
1682 | |
---|
1683 | for (i = 0; i < row_width; i++) |
---|
1684 | { |
---|
1685 | save[0] = *(--sp); |
---|
1686 | save[1] = *(--sp); |
---|
1687 | *(--dp) = *(--sp); |
---|
1688 | *(--dp) = *(--sp); |
---|
1689 | *(--dp) = *(--sp); |
---|
1690 | *(--dp) = *(--sp); |
---|
1691 | *(--dp) = *(--sp); |
---|
1692 | *(--dp) = *(--sp); |
---|
1693 | *(--dp) = save[0]; |
---|
1694 | *(--dp) = save[1]; |
---|
1695 | } |
---|
1696 | } |
---|
1697 | } |
---|
1698 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
---|
1699 | { |
---|
1700 | /* This converts from GA to AG */ |
---|
1701 | if (row_info->bit_depth == 8) |
---|
1702 | { |
---|
1703 | png_bytep sp = row + row_info->rowbytes; |
---|
1704 | png_bytep dp = sp; |
---|
1705 | png_byte save; |
---|
1706 | png_uint_32 i; |
---|
1707 | |
---|
1708 | for (i = 0; i < row_width; i++) |
---|
1709 | { |
---|
1710 | save = *(--sp); |
---|
1711 | *(--dp) = *(--sp); |
---|
1712 | *(--dp) = save; |
---|
1713 | } |
---|
1714 | } |
---|
1715 | /* This converts from GGAA to AAGG */ |
---|
1716 | else |
---|
1717 | { |
---|
1718 | png_bytep sp = row + row_info->rowbytes; |
---|
1719 | png_bytep dp = sp; |
---|
1720 | png_byte save[2]; |
---|
1721 | png_uint_32 i; |
---|
1722 | |
---|
1723 | for (i = 0; i < row_width; i++) |
---|
1724 | { |
---|
1725 | save[0] = *(--sp); |
---|
1726 | save[1] = *(--sp); |
---|
1727 | *(--dp) = *(--sp); |
---|
1728 | *(--dp) = *(--sp); |
---|
1729 | *(--dp) = save[0]; |
---|
1730 | *(--dp) = save[1]; |
---|
1731 | } |
---|
1732 | } |
---|
1733 | } |
---|
1734 | } |
---|
1735 | } |
---|
1736 | #endif |
---|
1737 | |
---|
1738 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
---|
1739 | void /* PRIVATE */ |
---|
1740 | png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) |
---|
1741 | { |
---|
1742 | png_debug(1, "in png_do_read_invert_alpha\n"); |
---|
1743 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1744 | if (row != NULL && row_info != NULL) |
---|
1745 | #endif |
---|
1746 | { |
---|
1747 | png_uint_32 row_width = row_info->width; |
---|
1748 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
---|
1749 | { |
---|
1750 | /* This inverts the alpha channel in RGBA */ |
---|
1751 | if (row_info->bit_depth == 8) |
---|
1752 | { |
---|
1753 | png_bytep sp = row + row_info->rowbytes; |
---|
1754 | png_bytep dp = sp; |
---|
1755 | png_uint_32 i; |
---|
1756 | |
---|
1757 | for (i = 0; i < row_width; i++) |
---|
1758 | { |
---|
1759 | *(--dp) = (png_byte)(255 - *(--sp)); |
---|
1760 | |
---|
1761 | /* This does nothing: |
---|
1762 | *(--dp) = *(--sp); |
---|
1763 | *(--dp) = *(--sp); |
---|
1764 | *(--dp) = *(--sp); |
---|
1765 | We can replace it with: |
---|
1766 | */ |
---|
1767 | sp-=3; |
---|
1768 | dp=sp; |
---|
1769 | } |
---|
1770 | } |
---|
1771 | /* This inverts the alpha channel in RRGGBBAA */ |
---|
1772 | else |
---|
1773 | { |
---|
1774 | png_bytep sp = row + row_info->rowbytes; |
---|
1775 | png_bytep dp = sp; |
---|
1776 | png_uint_32 i; |
---|
1777 | |
---|
1778 | for (i = 0; i < row_width; i++) |
---|
1779 | { |
---|
1780 | *(--dp) = (png_byte)(255 - *(--sp)); |
---|
1781 | *(--dp) = (png_byte)(255 - *(--sp)); |
---|
1782 | |
---|
1783 | /* This does nothing: |
---|
1784 | *(--dp) = *(--sp); |
---|
1785 | *(--dp) = *(--sp); |
---|
1786 | *(--dp) = *(--sp); |
---|
1787 | *(--dp) = *(--sp); |
---|
1788 | *(--dp) = *(--sp); |
---|
1789 | *(--dp) = *(--sp); |
---|
1790 | We can replace it with: |
---|
1791 | */ |
---|
1792 | sp-=6; |
---|
1793 | dp=sp; |
---|
1794 | } |
---|
1795 | } |
---|
1796 | } |
---|
1797 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
---|
1798 | { |
---|
1799 | /* This inverts the alpha channel in GA */ |
---|
1800 | if (row_info->bit_depth == 8) |
---|
1801 | { |
---|
1802 | png_bytep sp = row + row_info->rowbytes; |
---|
1803 | png_bytep dp = sp; |
---|
1804 | png_uint_32 i; |
---|
1805 | |
---|
1806 | for (i = 0; i < row_width; i++) |
---|
1807 | { |
---|
1808 | *(--dp) = (png_byte)(255 - *(--sp)); |
---|
1809 | *(--dp) = *(--sp); |
---|
1810 | } |
---|
1811 | } |
---|
1812 | /* This inverts the alpha channel in GGAA */ |
---|
1813 | else |
---|
1814 | { |
---|
1815 | png_bytep sp = row + row_info->rowbytes; |
---|
1816 | png_bytep dp = sp; |
---|
1817 | png_uint_32 i; |
---|
1818 | |
---|
1819 | for (i = 0; i < row_width; i++) |
---|
1820 | { |
---|
1821 | *(--dp) = (png_byte)(255 - *(--sp)); |
---|
1822 | *(--dp) = (png_byte)(255 - *(--sp)); |
---|
1823 | /* |
---|
1824 | *(--dp) = *(--sp); |
---|
1825 | *(--dp) = *(--sp); |
---|
1826 | */ |
---|
1827 | sp-=2; |
---|
1828 | dp=sp; |
---|
1829 | } |
---|
1830 | } |
---|
1831 | } |
---|
1832 | } |
---|
1833 | } |
---|
1834 | #endif |
---|
1835 | |
---|
1836 | #if defined(PNG_READ_FILLER_SUPPORTED) |
---|
1837 | /* Add filler channel if we have RGB color */ |
---|
1838 | void /* PRIVATE */ |
---|
1839 | png_do_read_filler(png_row_infop row_info, png_bytep row, |
---|
1840 | png_uint_32 filler, png_uint_32 flags) |
---|
1841 | { |
---|
1842 | png_uint_32 i; |
---|
1843 | png_uint_32 row_width = row_info->width; |
---|
1844 | |
---|
1845 | png_byte hi_filler = (png_byte)((filler>>8) & 0xff); |
---|
1846 | png_byte lo_filler = (png_byte)(filler & 0xff); |
---|
1847 | |
---|
1848 | png_debug(1, "in png_do_read_filler\n"); |
---|
1849 | if ( |
---|
1850 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
1851 | row != NULL && row_info != NULL && |
---|
1852 | #endif |
---|
1853 | row_info->color_type == PNG_COLOR_TYPE_GRAY) |
---|
1854 | { |
---|
1855 | if(row_info->bit_depth == 8) |
---|
1856 | { |
---|
1857 | /* This changes the data from G to GX */ |
---|
1858 | if (flags & PNG_FLAG_FILLER_AFTER) |
---|
1859 | { |
---|
1860 | png_bytep sp = row + (png_size_t)row_width; |
---|
1861 | png_bytep dp = sp + (png_size_t)row_width; |
---|
1862 | for (i = 1; i < row_width; i++) |
---|
1863 | { |
---|
1864 | *(--dp) = lo_filler; |
---|
1865 | *(--dp) = *(--sp); |
---|
1866 | } |
---|
1867 | *(--dp) = lo_filler; |
---|
1868 | row_info->channels = 2; |
---|
1869 | row_info->pixel_depth = 16; |
---|
1870 | row_info->rowbytes = row_width * 2; |
---|
1871 | } |
---|
1872 | /* This changes the data from G to XG */ |
---|
1873 | else |
---|
1874 | { |
---|
1875 | png_bytep sp = row + (png_size_t)row_width; |
---|
1876 | png_bytep dp = sp + (png_size_t)row_width; |
---|
1877 | for (i = 0; i < row_width; i++) |
---|
1878 | { |
---|
1879 | *(--dp) = *(--sp); |
---|
1880 | *(--dp) = lo_filler; |
---|
1881 | } |
---|
1882 | row_info->channels = 2; |
---|
1883 | row_info->pixel_depth = 16; |
---|
1884 | row_info->rowbytes = row_width * 2; |
---|
1885 | } |
---|
1886 | } |
---|
1887 | else if(row_info->bit_depth == 16) |
---|
1888 | { |
---|
1889 | /* This changes the data from GG to GGXX */ |
---|
1890 | if (flags & PNG_FLAG_FILLER_AFTER) |
---|
1891 | { |
---|
1892 | png_bytep sp = row + (png_size_t)row_width * 2; |
---|
1893 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
1894 | for (i = 1; i < row_width; i++) |
---|
1895 | { |
---|
1896 | *(--dp) = hi_filler; |
---|
1897 | *(--dp) = lo_filler; |
---|
1898 | *(--dp) = *(--sp); |
---|
1899 | *(--dp) = *(--sp); |
---|
1900 | } |
---|
1901 | *(--dp) = hi_filler; |
---|
1902 | *(--dp) = lo_filler; |
---|
1903 | row_info->channels = 2; |
---|
1904 | row_info->pixel_depth = 32; |
---|
1905 | row_info->rowbytes = row_width * 4; |
---|
1906 | } |
---|
1907 | /* This changes the data from GG to XXGG */ |
---|
1908 | else |
---|
1909 | { |
---|
1910 | png_bytep sp = row + (png_size_t)row_width * 2; |
---|
1911 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
1912 | for (i = 0; i < row_width; i++) |
---|
1913 | { |
---|
1914 | *(--dp) = *(--sp); |
---|
1915 | *(--dp) = *(--sp); |
---|
1916 | *(--dp) = hi_filler; |
---|
1917 | *(--dp) = lo_filler; |
---|
1918 | } |
---|
1919 | row_info->channels = 2; |
---|
1920 | row_info->pixel_depth = 32; |
---|
1921 | row_info->rowbytes = row_width * 4; |
---|
1922 | } |
---|
1923 | } |
---|
1924 | } /* COLOR_TYPE == GRAY */ |
---|
1925 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
---|
1926 | { |
---|
1927 | if(row_info->bit_depth == 8) |
---|
1928 | { |
---|
1929 | /* This changes the data from RGB to RGBX */ |
---|
1930 | if (flags & PNG_FLAG_FILLER_AFTER) |
---|
1931 | { |
---|
1932 | png_bytep sp = row + (png_size_t)row_width * 6; |
---|
1933 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
1934 | for (i = 1; i < row_width; i++) |
---|
1935 | { |
---|
1936 | *(--dp) = lo_filler; |
---|
1937 | *(--dp) = *(--sp); |
---|
1938 | *(--dp) = *(--sp); |
---|
1939 | *(--dp) = *(--sp); |
---|
1940 | } |
---|
1941 | *(--dp) = lo_filler; |
---|
1942 | row_info->channels = 4; |
---|
1943 | row_info->pixel_depth = 32; |
---|
1944 | row_info->rowbytes = row_width * 4; |
---|
1945 | } |
---|
1946 | /* This changes the data from RGB to XRGB */ |
---|
1947 | else |
---|
1948 | { |
---|
1949 | png_bytep sp = row + (png_size_t)row_width * 3; |
---|
1950 | png_bytep dp = sp + (png_size_t)row_width; |
---|
1951 | for (i = 0; i < row_width; i++) |
---|
1952 | { |
---|
1953 | *(--dp) = *(--sp); |
---|
1954 | *(--dp) = *(--sp); |
---|
1955 | *(--dp) = *(--sp); |
---|
1956 | *(--dp) = lo_filler; |
---|
1957 | } |
---|
1958 | row_info->channels = 4; |
---|
1959 | row_info->pixel_depth = 32; |
---|
1960 | row_info->rowbytes = row_width * 4; |
---|
1961 | } |
---|
1962 | } |
---|
1963 | else if(row_info->bit_depth == 16) |
---|
1964 | { |
---|
1965 | /* This changes the data from RRGGBB to RRGGBBXX */ |
---|
1966 | if (flags & PNG_FLAG_FILLER_AFTER) |
---|
1967 | { |
---|
1968 | png_bytep sp = row + (png_size_t)row_width * 6; |
---|
1969 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
1970 | for (i = 1; i < row_width; i++) |
---|
1971 | { |
---|
1972 | *(--dp) = hi_filler; |
---|
1973 | *(--dp) = lo_filler; |
---|
1974 | *(--dp) = *(--sp); |
---|
1975 | *(--dp) = *(--sp); |
---|
1976 | *(--dp) = *(--sp); |
---|
1977 | *(--dp) = *(--sp); |
---|
1978 | *(--dp) = *(--sp); |
---|
1979 | *(--dp) = *(--sp); |
---|
1980 | } |
---|
1981 | *(--dp) = hi_filler; |
---|
1982 | *(--dp) = lo_filler; |
---|
1983 | row_info->channels = 4; |
---|
1984 | row_info->pixel_depth = 64; |
---|
1985 | row_info->rowbytes = row_width * 8; |
---|
1986 | } |
---|
1987 | /* This changes the data from RRGGBB to XXRRGGBB */ |
---|
1988 | else |
---|
1989 | { |
---|
1990 | png_bytep sp = row + (png_size_t)row_width * 6; |
---|
1991 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
1992 | for (i = 0; i < row_width; i++) |
---|
1993 | { |
---|
1994 | *(--dp) = *(--sp); |
---|
1995 | *(--dp) = *(--sp); |
---|
1996 | *(--dp) = *(--sp); |
---|
1997 | *(--dp) = *(--sp); |
---|
1998 | *(--dp) = *(--sp); |
---|
1999 | *(--dp) = *(--sp); |
---|
2000 | *(--dp) = hi_filler; |
---|
2001 | *(--dp) = lo_filler; |
---|
2002 | } |
---|
2003 | row_info->channels = 4; |
---|
2004 | row_info->pixel_depth = 64; |
---|
2005 | row_info->rowbytes = row_width * 8; |
---|
2006 | } |
---|
2007 | } |
---|
2008 | } /* COLOR_TYPE == RGB */ |
---|
2009 | } |
---|
2010 | #endif |
---|
2011 | |
---|
2012 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
---|
2013 | /* expand grayscale files to RGB, with or without alpha */ |
---|
2014 | void /* PRIVATE */ |
---|
2015 | png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
---|
2016 | { |
---|
2017 | png_uint_32 i; |
---|
2018 | png_uint_32 row_width = row_info->width; |
---|
2019 | |
---|
2020 | png_debug(1, "in png_do_gray_to_rgb\n"); |
---|
2021 | if (row_info->bit_depth >= 8 && |
---|
2022 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
2023 | row != NULL && row_info != NULL && |
---|
2024 | #endif |
---|
2025 | !(row_info->color_type & PNG_COLOR_MASK_COLOR)) |
---|
2026 | { |
---|
2027 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
---|
2028 | { |
---|
2029 | if (row_info->bit_depth == 8) |
---|
2030 | { |
---|
2031 | png_bytep sp = row + (png_size_t)row_width - 1; |
---|
2032 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
2033 | for (i = 0; i < row_width; i++) |
---|
2034 | { |
---|
2035 | *(dp--) = *sp; |
---|
2036 | *(dp--) = *sp; |
---|
2037 | *(dp--) = *(sp--); |
---|
2038 | } |
---|
2039 | } |
---|
2040 | else |
---|
2041 | { |
---|
2042 | png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
---|
2043 | png_bytep dp = sp + (png_size_t)row_width * 4; |
---|
2044 | for (i = 0; i < row_width; i++) |
---|
2045 | { |
---|
2046 | *(dp--) = *sp; |
---|
2047 | *(dp--) = *(sp - 1); |
---|
2048 | *(dp--) = *sp; |
---|
2049 | *(dp--) = *(sp - 1); |
---|
2050 | *(dp--) = *(sp--); |
---|
2051 | *(dp--) = *(sp--); |
---|
2052 | } |
---|
2053 | } |
---|
2054 | } |
---|
2055 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
---|
2056 | { |
---|
2057 | if (row_info->bit_depth == 8) |
---|
2058 | { |
---|
2059 | png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
---|
2060 | png_bytep dp = sp + (png_size_t)row_width * 2; |
---|
2061 | for (i = 0; i < row_width; i++) |
---|
2062 | { |
---|
2063 | *(dp--) = *(sp--); |
---|
2064 | *(dp--) = *sp; |
---|
2065 | *(dp--) = *sp; |
---|
2066 | *(dp--) = *(sp--); |
---|
2067 | } |
---|
2068 | } |
---|
2069 | else |
---|
2070 | { |
---|
2071 | png_bytep sp = row + (png_size_t)row_width * 4 - 1; |
---|
2072 | png_bytep dp = sp + (png_size_t)row_width * 4; |
---|
2073 | for (i = 0; i < row_width; i++) |
---|
2074 | { |
---|
2075 | *(dp--) = *(sp--); |
---|
2076 | *(dp--) = *(sp--); |
---|
2077 | *(dp--) = *sp; |
---|
2078 | *(dp--) = *(sp - 1); |
---|
2079 | *(dp--) = *sp; |
---|
2080 | *(dp--) = *(sp - 1); |
---|
2081 | *(dp--) = *(sp--); |
---|
2082 | *(dp--) = *(sp--); |
---|
2083 | } |
---|
2084 | } |
---|
2085 | } |
---|
2086 | row_info->channels += (png_byte)2; |
---|
2087 | row_info->color_type |= PNG_COLOR_MASK_COLOR; |
---|
2088 | row_info->pixel_depth = (png_byte)(row_info->channels * |
---|
2089 | row_info->bit_depth); |
---|
2090 | row_info->rowbytes = ((row_width * |
---|
2091 | row_info->pixel_depth + 7) >> 3); |
---|
2092 | } |
---|
2093 | } |
---|
2094 | #endif |
---|
2095 | |
---|
2096 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
---|
2097 | /* reduce RGB files to grayscale, with or without alpha |
---|
2098 | * using the equation given in Poynton's ColorFAQ at |
---|
2099 | * <http://www.inforamp.net/~poynton/> |
---|
2100 | * Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net |
---|
2101 | * |
---|
2102 | * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
---|
2103 | * |
---|
2104 | * We approximate this with |
---|
2105 | * |
---|
2106 | * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B |
---|
2107 | * |
---|
2108 | * which can be expressed with integers as |
---|
2109 | * |
---|
2110 | * Y = (6969 * R + 23434 * G + 2365 * B)/32768 |
---|
2111 | * |
---|
2112 | * The calculation is to be done in a linear colorspace. |
---|
2113 | * |
---|
2114 | * Other integer coefficents can be used via png_set_rgb_to_gray(). |
---|
2115 | */ |
---|
2116 | int /* PRIVATE */ |
---|
2117 | png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) |
---|
2118 | |
---|
2119 | { |
---|
2120 | png_uint_32 i; |
---|
2121 | |
---|
2122 | png_uint_32 row_width = row_info->width; |
---|
2123 | int rgb_error = 0; |
---|
2124 | |
---|
2125 | png_debug(1, "in png_do_rgb_to_gray\n"); |
---|
2126 | if ( |
---|
2127 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
2128 | row != NULL && row_info != NULL && |
---|
2129 | #endif |
---|
2130 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
---|
2131 | { |
---|
2132 | png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; |
---|
2133 | png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; |
---|
2134 | png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; |
---|
2135 | |
---|
2136 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
---|
2137 | { |
---|
2138 | if (row_info->bit_depth == 8) |
---|
2139 | { |
---|
2140 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2141 | if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
---|
2142 | { |
---|
2143 | png_bytep sp = row; |
---|
2144 | png_bytep dp = row; |
---|
2145 | |
---|
2146 | for (i = 0; i < row_width; i++) |
---|
2147 | { |
---|
2148 | png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
---|
2149 | png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
---|
2150 | png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
---|
2151 | if(red != green || red != blue) |
---|
2152 | { |
---|
2153 | rgb_error |= 1; |
---|
2154 | *(dp++) = png_ptr->gamma_from_1[ |
---|
2155 | (rc*red+gc*green+bc*blue)>>15]; |
---|
2156 | } |
---|
2157 | else |
---|
2158 | *(dp++) = *(sp-1); |
---|
2159 | } |
---|
2160 | } |
---|
2161 | else |
---|
2162 | #endif |
---|
2163 | { |
---|
2164 | png_bytep sp = row; |
---|
2165 | png_bytep dp = row; |
---|
2166 | for (i = 0; i < row_width; i++) |
---|
2167 | { |
---|
2168 | png_byte red = *(sp++); |
---|
2169 | png_byte green = *(sp++); |
---|
2170 | png_byte blue = *(sp++); |
---|
2171 | if(red != green || red != blue) |
---|
2172 | { |
---|
2173 | rgb_error |= 1; |
---|
2174 | *(dp++) = (png_byte)((rc*red+gc*green+bc*blue)>>15); |
---|
2175 | } |
---|
2176 | else |
---|
2177 | *(dp++) = *(sp-1); |
---|
2178 | } |
---|
2179 | } |
---|
2180 | } |
---|
2181 | |
---|
2182 | else /* RGB bit_depth == 16 */ |
---|
2183 | { |
---|
2184 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2185 | if (png_ptr->gamma_16_to_1 != NULL && |
---|
2186 | png_ptr->gamma_16_from_1 != NULL) |
---|
2187 | { |
---|
2188 | png_bytep sp = row; |
---|
2189 | png_bytep dp = row; |
---|
2190 | for (i = 0; i < row_width; i++) |
---|
2191 | { |
---|
2192 | png_uint_16 red, green, blue, w; |
---|
2193 | |
---|
2194 | red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2195 | green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2196 | blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2197 | |
---|
2198 | if(red == green && red == blue) |
---|
2199 | w = red; |
---|
2200 | else |
---|
2201 | { |
---|
2202 | png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
---|
2203 | png_ptr->gamma_shift][red>>8]; |
---|
2204 | png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
---|
2205 | png_ptr->gamma_shift][green>>8]; |
---|
2206 | png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
---|
2207 | png_ptr->gamma_shift][blue>>8]; |
---|
2208 | png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 |
---|
2209 | + bc*blue_1)>>15); |
---|
2210 | w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
---|
2211 | png_ptr->gamma_shift][gray16 >> 8]; |
---|
2212 | rgb_error |= 1; |
---|
2213 | } |
---|
2214 | |
---|
2215 | *(dp++) = (png_byte)((w>>8) & 0xff); |
---|
2216 | *(dp++) = (png_byte)(w & 0xff); |
---|
2217 | } |
---|
2218 | } |
---|
2219 | else |
---|
2220 | #endif |
---|
2221 | { |
---|
2222 | png_bytep sp = row; |
---|
2223 | png_bytep dp = row; |
---|
2224 | for (i = 0; i < row_width; i++) |
---|
2225 | { |
---|
2226 | png_uint_16 red, green, blue, gray16; |
---|
2227 | |
---|
2228 | red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2229 | green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2230 | blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2231 | |
---|
2232 | if(red != green || red != blue) |
---|
2233 | rgb_error |= 1; |
---|
2234 | gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
---|
2235 | *(dp++) = (png_byte)((gray16>>8) & 0xff); |
---|
2236 | *(dp++) = (png_byte)(gray16 & 0xff); |
---|
2237 | } |
---|
2238 | } |
---|
2239 | } |
---|
2240 | } |
---|
2241 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
---|
2242 | { |
---|
2243 | if (row_info->bit_depth == 8) |
---|
2244 | { |
---|
2245 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2246 | if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
---|
2247 | { |
---|
2248 | png_bytep sp = row; |
---|
2249 | png_bytep dp = row; |
---|
2250 | for (i = 0; i < row_width; i++) |
---|
2251 | { |
---|
2252 | png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
---|
2253 | png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
---|
2254 | png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
---|
2255 | if(red != green || red != blue) |
---|
2256 | rgb_error |= 1; |
---|
2257 | *(dp++) = png_ptr->gamma_from_1 |
---|
2258 | [(rc*red + gc*green + bc*blue)>>15]; |
---|
2259 | *(dp++) = *(sp++); /* alpha */ |
---|
2260 | } |
---|
2261 | } |
---|
2262 | else |
---|
2263 | #endif |
---|
2264 | { |
---|
2265 | png_bytep sp = row; |
---|
2266 | png_bytep dp = row; |
---|
2267 | for (i = 0; i < row_width; i++) |
---|
2268 | { |
---|
2269 | png_byte red = *(sp++); |
---|
2270 | png_byte green = *(sp++); |
---|
2271 | png_byte blue = *(sp++); |
---|
2272 | if(red != green || red != blue) |
---|
2273 | rgb_error |= 1; |
---|
2274 | *(dp++) = (png_byte)((gc*red + gc*green + bc*blue)>>8); |
---|
2275 | *(dp++) = *(sp++); /* alpha */ |
---|
2276 | } |
---|
2277 | } |
---|
2278 | } |
---|
2279 | else /* RGBA bit_depth == 16 */ |
---|
2280 | { |
---|
2281 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2282 | if (png_ptr->gamma_16_to_1 != NULL && |
---|
2283 | png_ptr->gamma_16_from_1 != NULL) |
---|
2284 | { |
---|
2285 | png_bytep sp = row; |
---|
2286 | png_bytep dp = row; |
---|
2287 | for (i = 0; i < row_width; i++) |
---|
2288 | { |
---|
2289 | png_uint_16 red, green, blue, w; |
---|
2290 | |
---|
2291 | red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2292 | green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2293 | blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
---|
2294 | |
---|
2295 | if(red == green && red == blue) |
---|
2296 | w = red; |
---|
2297 | else |
---|
2298 | { |
---|
2299 | png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
---|
2300 | png_ptr->gamma_shift][red>>8]; |
---|
2301 | png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
---|
2302 | png_ptr->gamma_shift][green>>8]; |
---|
2303 | png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
---|
2304 | png_ptr->gamma_shift][blue>>8]; |
---|
2305 | png_uint_16 gray16 = (png_uint_16)((rc * red_1 |
---|
2306 | + gc * green_1 + bc * blue_1)>>15); |
---|
2307 | w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
---|
2308 | png_ptr->gamma_shift][gray16 >> 8]; |
---|
2309 | rgb_error |= 1; |
---|
2310 | } |
---|
2311 | |
---|
2312 | *(dp++) = (png_byte)((w>>8) & 0xff); |
---|
2313 | *(dp++) = (png_byte)(w & 0xff); |
---|
2314 | *(dp++) = *(sp++); /* alpha */ |
---|
2315 | *(dp++) = *(sp++); |
---|
2316 | } |
---|
2317 | } |
---|
2318 | else |
---|
2319 | #endif |
---|
2320 | { |
---|
2321 | png_bytep sp = row; |
---|
2322 | png_bytep dp = row; |
---|
2323 | for (i = 0; i < row_width; i++) |
---|
2324 | { |
---|
2325 | png_uint_16 red, green, blue, gray16; |
---|
2326 | red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
---|
2327 | green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
---|
2328 | blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
---|
2329 | if(red != green || red != blue) |
---|
2330 | rgb_error |= 1; |
---|
2331 | gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
---|
2332 | *(dp++) = (png_byte)((gray16>>8) & 0xff); |
---|
2333 | *(dp++) = (png_byte)(gray16 & 0xff); |
---|
2334 | *(dp++) = *(sp++); /* alpha */ |
---|
2335 | *(dp++) = *(sp++); |
---|
2336 | } |
---|
2337 | } |
---|
2338 | } |
---|
2339 | } |
---|
2340 | row_info->channels -= (png_byte)2; |
---|
2341 | row_info->color_type &= ~PNG_COLOR_MASK_COLOR; |
---|
2342 | row_info->pixel_depth = (png_byte)(row_info->channels * |
---|
2343 | row_info->bit_depth); |
---|
2344 | row_info->rowbytes = ((row_width * |
---|
2345 | row_info->pixel_depth + 7) >> 3); |
---|
2346 | } |
---|
2347 | return rgb_error; |
---|
2348 | } |
---|
2349 | #endif |
---|
2350 | |
---|
2351 | /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
---|
2352 | * large of png_color. This lets grayscale images be treated as |
---|
2353 | * paletted. Most useful for gamma correction and simplification |
---|
2354 | * of code. |
---|
2355 | */ |
---|
2356 | void PNGAPI |
---|
2357 | png_build_grayscale_palette(int bit_depth, png_colorp palette) |
---|
2358 | { |
---|
2359 | int num_palette; |
---|
2360 | int color_inc; |
---|
2361 | int i; |
---|
2362 | int v; |
---|
2363 | |
---|
2364 | png_debug(1, "in png_do_build_grayscale_palette\n"); |
---|
2365 | if (palette == NULL) |
---|
2366 | return; |
---|
2367 | |
---|
2368 | switch (bit_depth) |
---|
2369 | { |
---|
2370 | case 1: |
---|
2371 | num_palette = 2; |
---|
2372 | color_inc = 0xff; |
---|
2373 | break; |
---|
2374 | case 2: |
---|
2375 | num_palette = 4; |
---|
2376 | color_inc = 0x55; |
---|
2377 | break; |
---|
2378 | case 4: |
---|
2379 | num_palette = 16; |
---|
2380 | color_inc = 0x11; |
---|
2381 | break; |
---|
2382 | case 8: |
---|
2383 | num_palette = 256; |
---|
2384 | color_inc = 1; |
---|
2385 | break; |
---|
2386 | default: |
---|
2387 | num_palette = 0; |
---|
2388 | color_inc = 0; |
---|
2389 | break; |
---|
2390 | } |
---|
2391 | |
---|
2392 | for (i = 0, v = 0; i < num_palette; i++, v += color_inc) |
---|
2393 | { |
---|
2394 | palette[i].red = (png_byte)v; |
---|
2395 | palette[i].green = (png_byte)v; |
---|
2396 | palette[i].blue = (png_byte)v; |
---|
2397 | } |
---|
2398 | } |
---|
2399 | |
---|
2400 | /* This function is currently unused. Do we really need it? */ |
---|
2401 | #if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED) |
---|
2402 | void /* PRIVATE */ |
---|
2403 | png_correct_palette(png_structp png_ptr, png_colorp palette, |
---|
2404 | int num_palette) |
---|
2405 | { |
---|
2406 | png_debug(1, "in png_correct_palette\n"); |
---|
2407 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
---|
2408 | defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
---|
2409 | if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND)) |
---|
2410 | { |
---|
2411 | png_color back, back_1; |
---|
2412 | |
---|
2413 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
---|
2414 | { |
---|
2415 | back.red = png_ptr->gamma_table[png_ptr->background.red]; |
---|
2416 | back.green = png_ptr->gamma_table[png_ptr->background.green]; |
---|
2417 | back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
---|
2418 | |
---|
2419 | back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
---|
2420 | back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
---|
2421 | back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
---|
2422 | } |
---|
2423 | else |
---|
2424 | { |
---|
2425 | double g; |
---|
2426 | |
---|
2427 | g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); |
---|
2428 | |
---|
2429 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN || |
---|
2430 | fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) |
---|
2431 | { |
---|
2432 | back.red = png_ptr->background.red; |
---|
2433 | back.green = png_ptr->background.green; |
---|
2434 | back.blue = png_ptr->background.blue; |
---|
2435 | } |
---|
2436 | else |
---|
2437 | { |
---|
2438 | back.red = |
---|
2439 | (png_byte)(pow((double)png_ptr->background.red/255, g) * |
---|
2440 | 255.0 + 0.5); |
---|
2441 | back.green = |
---|
2442 | (png_byte)(pow((double)png_ptr->background.green/255, g) * |
---|
2443 | 255.0 + 0.5); |
---|
2444 | back.blue = |
---|
2445 | (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
---|
2446 | 255.0 + 0.5); |
---|
2447 | } |
---|
2448 | |
---|
2449 | g = 1.0 / png_ptr->background_gamma; |
---|
2450 | |
---|
2451 | back_1.red = |
---|
2452 | (png_byte)(pow((double)png_ptr->background.red/255, g) * |
---|
2453 | 255.0 + 0.5); |
---|
2454 | back_1.green = |
---|
2455 | (png_byte)(pow((double)png_ptr->background.green/255, g) * |
---|
2456 | 255.0 + 0.5); |
---|
2457 | back_1.blue = |
---|
2458 | (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
---|
2459 | 255.0 + 0.5); |
---|
2460 | } |
---|
2461 | |
---|
2462 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
2463 | { |
---|
2464 | png_uint_32 i; |
---|
2465 | |
---|
2466 | for (i = 0; i < (png_uint_32)num_palette; i++) |
---|
2467 | { |
---|
2468 | if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) |
---|
2469 | { |
---|
2470 | palette[i] = back; |
---|
2471 | } |
---|
2472 | else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
---|
2473 | { |
---|
2474 | png_byte v, w; |
---|
2475 | |
---|
2476 | v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; |
---|
2477 | png_composite(w, v, png_ptr->trans[i], back_1.red); |
---|
2478 | palette[i].red = png_ptr->gamma_from_1[w]; |
---|
2479 | |
---|
2480 | v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; |
---|
2481 | png_composite(w, v, png_ptr->trans[i], back_1.green); |
---|
2482 | palette[i].green = png_ptr->gamma_from_1[w]; |
---|
2483 | |
---|
2484 | v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; |
---|
2485 | png_composite(w, v, png_ptr->trans[i], back_1.blue); |
---|
2486 | palette[i].blue = png_ptr->gamma_from_1[w]; |
---|
2487 | } |
---|
2488 | else |
---|
2489 | { |
---|
2490 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
---|
2491 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
---|
2492 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
---|
2493 | } |
---|
2494 | } |
---|
2495 | } |
---|
2496 | else |
---|
2497 | { |
---|
2498 | int i; |
---|
2499 | |
---|
2500 | for (i = 0; i < num_palette; i++) |
---|
2501 | { |
---|
2502 | if (palette[i].red == (png_byte)png_ptr->trans_values.gray) |
---|
2503 | { |
---|
2504 | palette[i] = back; |
---|
2505 | } |
---|
2506 | else |
---|
2507 | { |
---|
2508 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
---|
2509 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
---|
2510 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
---|
2511 | } |
---|
2512 | } |
---|
2513 | } |
---|
2514 | } |
---|
2515 | else |
---|
2516 | #endif |
---|
2517 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2518 | if (png_ptr->transformations & PNG_GAMMA) |
---|
2519 | { |
---|
2520 | int i; |
---|
2521 | |
---|
2522 | for (i = 0; i < num_palette; i++) |
---|
2523 | { |
---|
2524 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
---|
2525 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
---|
2526 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
---|
2527 | } |
---|
2528 | } |
---|
2529 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2530 | else |
---|
2531 | #endif |
---|
2532 | #endif |
---|
2533 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2534 | if (png_ptr->transformations & PNG_BACKGROUND) |
---|
2535 | { |
---|
2536 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
2537 | { |
---|
2538 | png_color back; |
---|
2539 | |
---|
2540 | back.red = (png_byte)png_ptr->background.red; |
---|
2541 | back.green = (png_byte)png_ptr->background.green; |
---|
2542 | back.blue = (png_byte)png_ptr->background.blue; |
---|
2543 | |
---|
2544 | for (i = 0; i < (int)png_ptr->num_trans; i++) |
---|
2545 | { |
---|
2546 | if (png_ptr->trans[i] == 0) |
---|
2547 | { |
---|
2548 | palette[i].red = back.red; |
---|
2549 | palette[i].green = back.green; |
---|
2550 | palette[i].blue = back.blue; |
---|
2551 | } |
---|
2552 | else if (png_ptr->trans[i] != 0xff) |
---|
2553 | { |
---|
2554 | png_composite(palette[i].red, png_ptr->palette[i].red, |
---|
2555 | png_ptr->trans[i], back.red); |
---|
2556 | png_composite(palette[i].green, png_ptr->palette[i].green, |
---|
2557 | png_ptr->trans[i], back.green); |
---|
2558 | png_composite(palette[i].blue, png_ptr->palette[i].blue, |
---|
2559 | png_ptr->trans[i], back.blue); |
---|
2560 | } |
---|
2561 | } |
---|
2562 | } |
---|
2563 | else /* assume grayscale palette (what else could it be?) */ |
---|
2564 | { |
---|
2565 | int i; |
---|
2566 | |
---|
2567 | for (i = 0; i < num_palette; i++) |
---|
2568 | { |
---|
2569 | if (i == (png_byte)png_ptr->trans_values.gray) |
---|
2570 | { |
---|
2571 | palette[i].red = (png_byte)png_ptr->background.red; |
---|
2572 | palette[i].green = (png_byte)png_ptr->background.green; |
---|
2573 | palette[i].blue = (png_byte)png_ptr->background.blue; |
---|
2574 | } |
---|
2575 | } |
---|
2576 | } |
---|
2577 | } |
---|
2578 | #endif |
---|
2579 | } |
---|
2580 | #endif |
---|
2581 | |
---|
2582 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
---|
2583 | /* Replace any alpha or transparency with the supplied background color. |
---|
2584 | * "background" is already in the screen gamma, while "background_1" is |
---|
2585 | * at a gamma of 1.0. Paletted files have already been taken care of. |
---|
2586 | */ |
---|
2587 | void /* PRIVATE */ |
---|
2588 | png_do_background(png_row_infop row_info, png_bytep row, |
---|
2589 | png_color_16p trans_values, png_color_16p background |
---|
2590 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2591 | , png_color_16p background_1, |
---|
2592 | png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, |
---|
2593 | png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, |
---|
2594 | png_uint_16pp gamma_16_to_1, int gamma_shift |
---|
2595 | #endif |
---|
2596 | ) |
---|
2597 | { |
---|
2598 | png_bytep sp, dp; |
---|
2599 | png_uint_32 i; |
---|
2600 | png_uint_32 row_width=row_info->width; |
---|
2601 | int shift; |
---|
2602 | |
---|
2603 | png_debug(1, "in png_do_background\n"); |
---|
2604 | if (background != NULL && |
---|
2605 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
2606 | row != NULL && row_info != NULL && |
---|
2607 | #endif |
---|
2608 | (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || |
---|
2609 | (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values))) |
---|
2610 | { |
---|
2611 | switch (row_info->color_type) |
---|
2612 | { |
---|
2613 | case PNG_COLOR_TYPE_GRAY: |
---|
2614 | { |
---|
2615 | switch (row_info->bit_depth) |
---|
2616 | { |
---|
2617 | case 1: |
---|
2618 | { |
---|
2619 | sp = row; |
---|
2620 | shift = 7; |
---|
2621 | for (i = 0; i < row_width; i++) |
---|
2622 | { |
---|
2623 | if ((png_uint_16)((*sp >> shift) & 0x01) |
---|
2624 | == trans_values->gray) |
---|
2625 | { |
---|
2626 | *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
---|
2627 | *sp |= (png_byte)(background->gray << shift); |
---|
2628 | } |
---|
2629 | if (!shift) |
---|
2630 | { |
---|
2631 | shift = 7; |
---|
2632 | sp++; |
---|
2633 | } |
---|
2634 | else |
---|
2635 | shift--; |
---|
2636 | } |
---|
2637 | break; |
---|
2638 | } |
---|
2639 | case 2: |
---|
2640 | { |
---|
2641 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2642 | if (gamma_table != NULL) |
---|
2643 | { |
---|
2644 | sp = row; |
---|
2645 | shift = 6; |
---|
2646 | for (i = 0; i < row_width; i++) |
---|
2647 | { |
---|
2648 | if ((png_uint_16)((*sp >> shift) & 0x03) |
---|
2649 | == trans_values->gray) |
---|
2650 | { |
---|
2651 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
---|
2652 | *sp |= (png_byte)(background->gray << shift); |
---|
2653 | } |
---|
2654 | else |
---|
2655 | { |
---|
2656 | png_byte p = (png_byte)((*sp >> shift) & 0x03); |
---|
2657 | png_byte g = (png_byte)((gamma_table [p | (p << 2) | |
---|
2658 | (p << 4) | (p << 6)] >> 6) & 0x03); |
---|
2659 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
---|
2660 | *sp |= (png_byte)(g << shift); |
---|
2661 | } |
---|
2662 | if (!shift) |
---|
2663 | { |
---|
2664 | shift = 6; |
---|
2665 | sp++; |
---|
2666 | } |
---|
2667 | else |
---|
2668 | shift -= 2; |
---|
2669 | } |
---|
2670 | } |
---|
2671 | else |
---|
2672 | #endif |
---|
2673 | { |
---|
2674 | sp = row; |
---|
2675 | shift = 6; |
---|
2676 | for (i = 0; i < row_width; i++) |
---|
2677 | { |
---|
2678 | if ((png_uint_16)((*sp >> shift) & 0x03) |
---|
2679 | == trans_values->gray) |
---|
2680 | { |
---|
2681 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
---|
2682 | *sp |= (png_byte)(background->gray << shift); |
---|
2683 | } |
---|
2684 | if (!shift) |
---|
2685 | { |
---|
2686 | shift = 6; |
---|
2687 | sp++; |
---|
2688 | } |
---|
2689 | else |
---|
2690 | shift -= 2; |
---|
2691 | } |
---|
2692 | } |
---|
2693 | break; |
---|
2694 | } |
---|
2695 | case 4: |
---|
2696 | { |
---|
2697 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2698 | if (gamma_table != NULL) |
---|
2699 | { |
---|
2700 | sp = row; |
---|
2701 | shift = 4; |
---|
2702 | for (i = 0; i < row_width; i++) |
---|
2703 | { |
---|
2704 | if ((png_uint_16)((*sp >> shift) & 0x0f) |
---|
2705 | == trans_values->gray) |
---|
2706 | { |
---|
2707 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
---|
2708 | *sp |= (png_byte)(background->gray << shift); |
---|
2709 | } |
---|
2710 | else |
---|
2711 | { |
---|
2712 | png_byte p = (png_byte)((*sp >> shift) & 0x0f); |
---|
2713 | png_byte g = (png_byte)((gamma_table[p | |
---|
2714 | (p << 4)] >> 4) & 0x0f); |
---|
2715 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
---|
2716 | *sp |= (png_byte)(g << shift); |
---|
2717 | } |
---|
2718 | if (!shift) |
---|
2719 | { |
---|
2720 | shift = 4; |
---|
2721 | sp++; |
---|
2722 | } |
---|
2723 | else |
---|
2724 | shift -= 4; |
---|
2725 | } |
---|
2726 | } |
---|
2727 | else |
---|
2728 | #endif |
---|
2729 | { |
---|
2730 | sp = row; |
---|
2731 | shift = 4; |
---|
2732 | for (i = 0; i < row_width; i++) |
---|
2733 | { |
---|
2734 | if ((png_uint_16)((*sp >> shift) & 0x0f) |
---|
2735 | == trans_values->gray) |
---|
2736 | { |
---|
2737 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
---|
2738 | *sp |= (png_byte)(background->gray << shift); |
---|
2739 | } |
---|
2740 | if (!shift) |
---|
2741 | { |
---|
2742 | shift = 4; |
---|
2743 | sp++; |
---|
2744 | } |
---|
2745 | else |
---|
2746 | shift -= 4; |
---|
2747 | } |
---|
2748 | } |
---|
2749 | break; |
---|
2750 | } |
---|
2751 | case 8: |
---|
2752 | { |
---|
2753 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2754 | if (gamma_table != NULL) |
---|
2755 | { |
---|
2756 | sp = row; |
---|
2757 | for (i = 0; i < row_width; i++, sp++) |
---|
2758 | { |
---|
2759 | if (*sp == trans_values->gray) |
---|
2760 | { |
---|
2761 | *sp = (png_byte)background->gray; |
---|
2762 | } |
---|
2763 | else |
---|
2764 | { |
---|
2765 | *sp = gamma_table[*sp]; |
---|
2766 | } |
---|
2767 | } |
---|
2768 | } |
---|
2769 | else |
---|
2770 | #endif |
---|
2771 | { |
---|
2772 | sp = row; |
---|
2773 | for (i = 0; i < row_width; i++, sp++) |
---|
2774 | { |
---|
2775 | if (*sp == trans_values->gray) |
---|
2776 | { |
---|
2777 | *sp = (png_byte)background->gray; |
---|
2778 | } |
---|
2779 | } |
---|
2780 | } |
---|
2781 | break; |
---|
2782 | } |
---|
2783 | case 16: |
---|
2784 | { |
---|
2785 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2786 | if (gamma_16 != NULL) |
---|
2787 | { |
---|
2788 | sp = row; |
---|
2789 | for (i = 0; i < row_width; i++, sp += 2) |
---|
2790 | { |
---|
2791 | png_uint_16 v; |
---|
2792 | |
---|
2793 | v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
---|
2794 | if (v == trans_values->gray) |
---|
2795 | { |
---|
2796 | /* background is already in screen gamma */ |
---|
2797 | *sp = (png_byte)((background->gray >> 8) & 0xff); |
---|
2798 | *(sp + 1) = (png_byte)(background->gray & 0xff); |
---|
2799 | } |
---|
2800 | else |
---|
2801 | { |
---|
2802 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
---|
2803 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
2804 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
2805 | } |
---|
2806 | } |
---|
2807 | } |
---|
2808 | else |
---|
2809 | #endif |
---|
2810 | { |
---|
2811 | sp = row; |
---|
2812 | for (i = 0; i < row_width; i++, sp += 2) |
---|
2813 | { |
---|
2814 | png_uint_16 v; |
---|
2815 | |
---|
2816 | v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
---|
2817 | if (v == trans_values->gray) |
---|
2818 | { |
---|
2819 | *sp = (png_byte)((background->gray >> 8) & 0xff); |
---|
2820 | *(sp + 1) = (png_byte)(background->gray & 0xff); |
---|
2821 | } |
---|
2822 | } |
---|
2823 | } |
---|
2824 | break; |
---|
2825 | } |
---|
2826 | } |
---|
2827 | break; |
---|
2828 | } |
---|
2829 | case PNG_COLOR_TYPE_RGB: |
---|
2830 | { |
---|
2831 | if (row_info->bit_depth == 8) |
---|
2832 | { |
---|
2833 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2834 | if (gamma_table != NULL) |
---|
2835 | { |
---|
2836 | sp = row; |
---|
2837 | for (i = 0; i < row_width; i++, sp += 3) |
---|
2838 | { |
---|
2839 | if (*sp == trans_values->red && |
---|
2840 | *(sp + 1) == trans_values->green && |
---|
2841 | *(sp + 2) == trans_values->blue) |
---|
2842 | { |
---|
2843 | *sp = (png_byte)background->red; |
---|
2844 | *(sp + 1) = (png_byte)background->green; |
---|
2845 | *(sp + 2) = (png_byte)background->blue; |
---|
2846 | } |
---|
2847 | else |
---|
2848 | { |
---|
2849 | *sp = gamma_table[*sp]; |
---|
2850 | *(sp + 1) = gamma_table[*(sp + 1)]; |
---|
2851 | *(sp + 2) = gamma_table[*(sp + 2)]; |
---|
2852 | } |
---|
2853 | } |
---|
2854 | } |
---|
2855 | else |
---|
2856 | #endif |
---|
2857 | { |
---|
2858 | sp = row; |
---|
2859 | for (i = 0; i < row_width; i++, sp += 3) |
---|
2860 | { |
---|
2861 | if (*sp == trans_values->red && |
---|
2862 | *(sp + 1) == trans_values->green && |
---|
2863 | *(sp + 2) == trans_values->blue) |
---|
2864 | { |
---|
2865 | *sp = (png_byte)background->red; |
---|
2866 | *(sp + 1) = (png_byte)background->green; |
---|
2867 | *(sp + 2) = (png_byte)background->blue; |
---|
2868 | } |
---|
2869 | } |
---|
2870 | } |
---|
2871 | } |
---|
2872 | else /* if (row_info->bit_depth == 16) */ |
---|
2873 | { |
---|
2874 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2875 | if (gamma_16 != NULL) |
---|
2876 | { |
---|
2877 | sp = row; |
---|
2878 | for (i = 0; i < row_width; i++, sp += 6) |
---|
2879 | { |
---|
2880 | png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
---|
2881 | png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
---|
2882 | png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); |
---|
2883 | if (r == trans_values->red && g == trans_values->green && |
---|
2884 | b == trans_values->blue) |
---|
2885 | { |
---|
2886 | /* background is already in screen gamma */ |
---|
2887 | *sp = (png_byte)((background->red >> 8) & 0xff); |
---|
2888 | *(sp + 1) = (png_byte)(background->red & 0xff); |
---|
2889 | *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
---|
2890 | *(sp + 3) = (png_byte)(background->green & 0xff); |
---|
2891 | *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
---|
2892 | *(sp + 5) = (png_byte)(background->blue & 0xff); |
---|
2893 | } |
---|
2894 | else |
---|
2895 | { |
---|
2896 | png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
---|
2897 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
2898 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
2899 | v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
---|
2900 | *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
---|
2901 | *(sp + 3) = (png_byte)(v & 0xff); |
---|
2902 | v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
---|
2903 | *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
---|
2904 | *(sp + 5) = (png_byte)(v & 0xff); |
---|
2905 | } |
---|
2906 | } |
---|
2907 | } |
---|
2908 | else |
---|
2909 | #endif |
---|
2910 | { |
---|
2911 | sp = row; |
---|
2912 | for (i = 0; i < row_width; i++, sp += 6) |
---|
2913 | { |
---|
2914 | png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1)); |
---|
2915 | png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
---|
2916 | png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); |
---|
2917 | |
---|
2918 | if (r == trans_values->red && g == trans_values->green && |
---|
2919 | b == trans_values->blue) |
---|
2920 | { |
---|
2921 | *sp = (png_byte)((background->red >> 8) & 0xff); |
---|
2922 | *(sp + 1) = (png_byte)(background->red & 0xff); |
---|
2923 | *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
---|
2924 | *(sp + 3) = (png_byte)(background->green & 0xff); |
---|
2925 | *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
---|
2926 | *(sp + 5) = (png_byte)(background->blue & 0xff); |
---|
2927 | } |
---|
2928 | } |
---|
2929 | } |
---|
2930 | } |
---|
2931 | break; |
---|
2932 | } |
---|
2933 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
---|
2934 | { |
---|
2935 | if (row_info->bit_depth == 8) |
---|
2936 | { |
---|
2937 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2938 | if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
---|
2939 | gamma_table != NULL) |
---|
2940 | { |
---|
2941 | sp = row; |
---|
2942 | dp = row; |
---|
2943 | for (i = 0; i < row_width; i++, sp += 2, dp++) |
---|
2944 | { |
---|
2945 | png_uint_16 a = *(sp + 1); |
---|
2946 | |
---|
2947 | if (a == 0xff) |
---|
2948 | { |
---|
2949 | *dp = gamma_table[*sp]; |
---|
2950 | } |
---|
2951 | else if (a == 0) |
---|
2952 | { |
---|
2953 | /* background is already in screen gamma */ |
---|
2954 | *dp = (png_byte)background->gray; |
---|
2955 | } |
---|
2956 | else |
---|
2957 | { |
---|
2958 | png_byte v, w; |
---|
2959 | |
---|
2960 | v = gamma_to_1[*sp]; |
---|
2961 | png_composite(w, v, a, background_1->gray); |
---|
2962 | *dp = gamma_from_1[w]; |
---|
2963 | } |
---|
2964 | } |
---|
2965 | } |
---|
2966 | else |
---|
2967 | #endif |
---|
2968 | { |
---|
2969 | sp = row; |
---|
2970 | dp = row; |
---|
2971 | for (i = 0; i < row_width; i++, sp += 2, dp++) |
---|
2972 | { |
---|
2973 | png_byte a = *(sp + 1); |
---|
2974 | |
---|
2975 | if (a == 0xff) |
---|
2976 | { |
---|
2977 | *dp = *sp; |
---|
2978 | } |
---|
2979 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2980 | else if (a == 0) |
---|
2981 | { |
---|
2982 | *dp = (png_byte)background->gray; |
---|
2983 | } |
---|
2984 | else |
---|
2985 | { |
---|
2986 | png_composite(*dp, *sp, a, background_1->gray); |
---|
2987 | } |
---|
2988 | #else |
---|
2989 | *dp = (png_byte)background->gray; |
---|
2990 | #endif |
---|
2991 | } |
---|
2992 | } |
---|
2993 | } |
---|
2994 | else /* if (png_ptr->bit_depth == 16) */ |
---|
2995 | { |
---|
2996 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
2997 | if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
---|
2998 | gamma_16_to_1 != NULL) |
---|
2999 | { |
---|
3000 | sp = row; |
---|
3001 | dp = row; |
---|
3002 | for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
---|
3003 | { |
---|
3004 | png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
---|
3005 | |
---|
3006 | if (a == (png_uint_16)0xffff) |
---|
3007 | { |
---|
3008 | png_uint_16 v; |
---|
3009 | |
---|
3010 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
---|
3011 | *dp = (png_byte)((v >> 8) & 0xff); |
---|
3012 | *(dp + 1) = (png_byte)(v & 0xff); |
---|
3013 | } |
---|
3014 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3015 | else if (a == 0) |
---|
3016 | #else |
---|
3017 | else |
---|
3018 | #endif |
---|
3019 | { |
---|
3020 | /* background is already in screen gamma */ |
---|
3021 | *dp = (png_byte)((background->gray >> 8) & 0xff); |
---|
3022 | *(dp + 1) = (png_byte)(background->gray & 0xff); |
---|
3023 | } |
---|
3024 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3025 | else |
---|
3026 | { |
---|
3027 | png_uint_16 g, v, w; |
---|
3028 | |
---|
3029 | g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
---|
3030 | png_composite_16(v, g, a, background_1->gray); |
---|
3031 | w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; |
---|
3032 | *dp = (png_byte)((w >> 8) & 0xff); |
---|
3033 | *(dp + 1) = (png_byte)(w & 0xff); |
---|
3034 | } |
---|
3035 | #endif |
---|
3036 | } |
---|
3037 | } |
---|
3038 | else |
---|
3039 | #endif |
---|
3040 | { |
---|
3041 | sp = row; |
---|
3042 | dp = row; |
---|
3043 | for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
---|
3044 | { |
---|
3045 | png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
---|
3046 | if (a == (png_uint_16)0xffff) |
---|
3047 | { |
---|
3048 | png_memcpy(dp, sp, 2); |
---|
3049 | } |
---|
3050 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3051 | else if (a == 0) |
---|
3052 | #else |
---|
3053 | else |
---|
3054 | #endif |
---|
3055 | { |
---|
3056 | *dp = (png_byte)((background->gray >> 8) & 0xff); |
---|
3057 | *(dp + 1) = (png_byte)(background->gray & 0xff); |
---|
3058 | } |
---|
3059 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3060 | else |
---|
3061 | { |
---|
3062 | png_uint_16 g, v; |
---|
3063 | |
---|
3064 | g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
---|
3065 | png_composite_16(v, g, a, background_1->gray); |
---|
3066 | *dp = (png_byte)((v >> 8) & 0xff); |
---|
3067 | *(dp + 1) = (png_byte)(v & 0xff); |
---|
3068 | } |
---|
3069 | #endif |
---|
3070 | } |
---|
3071 | } |
---|
3072 | } |
---|
3073 | break; |
---|
3074 | } |
---|
3075 | case PNG_COLOR_TYPE_RGB_ALPHA: |
---|
3076 | { |
---|
3077 | if (row_info->bit_depth == 8) |
---|
3078 | { |
---|
3079 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3080 | if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
---|
3081 | gamma_table != NULL) |
---|
3082 | { |
---|
3083 | sp = row; |
---|
3084 | dp = row; |
---|
3085 | for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
---|
3086 | { |
---|
3087 | png_byte a = *(sp + 3); |
---|
3088 | |
---|
3089 | if (a == 0xff) |
---|
3090 | { |
---|
3091 | *dp = gamma_table[*sp]; |
---|
3092 | *(dp + 1) = gamma_table[*(sp + 1)]; |
---|
3093 | *(dp + 2) = gamma_table[*(sp + 2)]; |
---|
3094 | } |
---|
3095 | else if (a == 0) |
---|
3096 | { |
---|
3097 | /* background is already in screen gamma */ |
---|
3098 | *dp = (png_byte)background->red; |
---|
3099 | *(dp + 1) = (png_byte)background->green; |
---|
3100 | *(dp + 2) = (png_byte)background->blue; |
---|
3101 | } |
---|
3102 | else |
---|
3103 | { |
---|
3104 | png_byte v, w; |
---|
3105 | |
---|
3106 | v = gamma_to_1[*sp]; |
---|
3107 | png_composite(w, v, a, background_1->red); |
---|
3108 | *dp = gamma_from_1[w]; |
---|
3109 | v = gamma_to_1[*(sp + 1)]; |
---|
3110 | png_composite(w, v, a, background_1->green); |
---|
3111 | *(dp + 1) = gamma_from_1[w]; |
---|
3112 | v = gamma_to_1[*(sp + 2)]; |
---|
3113 | png_composite(w, v, a, background_1->blue); |
---|
3114 | *(dp + 2) = gamma_from_1[w]; |
---|
3115 | } |
---|
3116 | } |
---|
3117 | } |
---|
3118 | else |
---|
3119 | #endif |
---|
3120 | { |
---|
3121 | sp = row; |
---|
3122 | dp = row; |
---|
3123 | for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
---|
3124 | { |
---|
3125 | png_byte a = *(sp + 3); |
---|
3126 | |
---|
3127 | if (a == 0xff) |
---|
3128 | { |
---|
3129 | *dp = *sp; |
---|
3130 | *(dp + 1) = *(sp + 1); |
---|
3131 | *(dp + 2) = *(sp + 2); |
---|
3132 | } |
---|
3133 | else if (a == 0) |
---|
3134 | { |
---|
3135 | *dp = (png_byte)background->red; |
---|
3136 | *(dp + 1) = (png_byte)background->green; |
---|
3137 | *(dp + 2) = (png_byte)background->blue; |
---|
3138 | } |
---|
3139 | else |
---|
3140 | { |
---|
3141 | png_composite(*dp, *sp, a, background->red); |
---|
3142 | png_composite(*(dp + 1), *(sp + 1), a, |
---|
3143 | background->green); |
---|
3144 | png_composite(*(dp + 2), *(sp + 2), a, |
---|
3145 | background->blue); |
---|
3146 | } |
---|
3147 | } |
---|
3148 | } |
---|
3149 | } |
---|
3150 | else /* if (row_info->bit_depth == 16) */ |
---|
3151 | { |
---|
3152 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3153 | if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
---|
3154 | gamma_16_to_1 != NULL) |
---|
3155 | { |
---|
3156 | sp = row; |
---|
3157 | dp = row; |
---|
3158 | for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
---|
3159 | { |
---|
3160 | png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
---|
3161 | << 8) + (png_uint_16)(*(sp + 7))); |
---|
3162 | if (a == (png_uint_16)0xffff) |
---|
3163 | { |
---|
3164 | png_uint_16 v; |
---|
3165 | |
---|
3166 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
---|
3167 | *dp = (png_byte)((v >> 8) & 0xff); |
---|
3168 | *(dp + 1) = (png_byte)(v & 0xff); |
---|
3169 | v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
---|
3170 | *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
---|
3171 | *(dp + 3) = (png_byte)(v & 0xff); |
---|
3172 | v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
---|
3173 | *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
---|
3174 | *(dp + 5) = (png_byte)(v & 0xff); |
---|
3175 | } |
---|
3176 | else if (a == 0) |
---|
3177 | { |
---|
3178 | /* background is already in screen gamma */ |
---|
3179 | *dp = (png_byte)((background->red >> 8) & 0xff); |
---|
3180 | *(dp + 1) = (png_byte)(background->red & 0xff); |
---|
3181 | *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
---|
3182 | *(dp + 3) = (png_byte)(background->green & 0xff); |
---|
3183 | *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
---|
3184 | *(dp + 5) = (png_byte)(background->blue & 0xff); |
---|
3185 | } |
---|
3186 | else |
---|
3187 | { |
---|
3188 | png_uint_16 v, w, x; |
---|
3189 | |
---|
3190 | v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
---|
3191 | png_composite_16(w, v, a, background_1->red); |
---|
3192 | x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
---|
3193 | *dp = (png_byte)((x >> 8) & 0xff); |
---|
3194 | *(dp + 1) = (png_byte)(x & 0xff); |
---|
3195 | v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
---|
3196 | png_composite_16(w, v, a, background_1->green); |
---|
3197 | x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
---|
3198 | *(dp + 2) = (png_byte)((x >> 8) & 0xff); |
---|
3199 | *(dp + 3) = (png_byte)(x & 0xff); |
---|
3200 | v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
---|
3201 | png_composite_16(w, v, a, background_1->blue); |
---|
3202 | x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; |
---|
3203 | *(dp + 4) = (png_byte)((x >> 8) & 0xff); |
---|
3204 | *(dp + 5) = (png_byte)(x & 0xff); |
---|
3205 | } |
---|
3206 | } |
---|
3207 | } |
---|
3208 | else |
---|
3209 | #endif |
---|
3210 | { |
---|
3211 | sp = row; |
---|
3212 | dp = row; |
---|
3213 | for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
---|
3214 | { |
---|
3215 | png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
---|
3216 | << 8) + (png_uint_16)(*(sp + 7))); |
---|
3217 | if (a == (png_uint_16)0xffff) |
---|
3218 | { |
---|
3219 | png_memcpy(dp, sp, 6); |
---|
3220 | } |
---|
3221 | else if (a == 0) |
---|
3222 | { |
---|
3223 | *dp = (png_byte)((background->red >> 8) & 0xff); |
---|
3224 | *(dp + 1) = (png_byte)(background->red & 0xff); |
---|
3225 | *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
---|
3226 | *(dp + 3) = (png_byte)(background->green & 0xff); |
---|
3227 | *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
---|
3228 | *(dp + 5) = (png_byte)(background->blue & 0xff); |
---|
3229 | } |
---|
3230 | else |
---|
3231 | { |
---|
3232 | png_uint_16 v; |
---|
3233 | |
---|
3234 | png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
---|
3235 | png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
---|
3236 | + *(sp + 3)); |
---|
3237 | png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
---|
3238 | + *(sp + 5)); |
---|
3239 | |
---|
3240 | png_composite_16(v, r, a, background->red); |
---|
3241 | *dp = (png_byte)((v >> 8) & 0xff); |
---|
3242 | *(dp + 1) = (png_byte)(v & 0xff); |
---|
3243 | png_composite_16(v, g, a, background->green); |
---|
3244 | *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
---|
3245 | *(dp + 3) = (png_byte)(v & 0xff); |
---|
3246 | png_composite_16(v, b, a, background->blue); |
---|
3247 | *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
---|
3248 | *(dp + 5) = (png_byte)(v & 0xff); |
---|
3249 | } |
---|
3250 | } |
---|
3251 | } |
---|
3252 | } |
---|
3253 | break; |
---|
3254 | } |
---|
3255 | } |
---|
3256 | |
---|
3257 | if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
---|
3258 | { |
---|
3259 | row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; |
---|
3260 | row_info->channels--; |
---|
3261 | row_info->pixel_depth = (png_byte)(row_info->channels * |
---|
3262 | row_info->bit_depth); |
---|
3263 | row_info->rowbytes = ((row_width * |
---|
3264 | row_info->pixel_depth + 7) >> 3); |
---|
3265 | } |
---|
3266 | } |
---|
3267 | } |
---|
3268 | #endif |
---|
3269 | |
---|
3270 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3271 | /* Gamma correct the image, avoiding the alpha channel. Make sure |
---|
3272 | * you do this after you deal with the transparency issue on grayscale |
---|
3273 | * or RGB images. If your bit depth is 8, use gamma_table, if it |
---|
3274 | * is 16, use gamma_16_table and gamma_shift. Build these with |
---|
3275 | * build_gamma_table(). |
---|
3276 | */ |
---|
3277 | void /* PRIVATE */ |
---|
3278 | png_do_gamma(png_row_infop row_info, png_bytep row, |
---|
3279 | png_bytep gamma_table, png_uint_16pp gamma_16_table, |
---|
3280 | int gamma_shift) |
---|
3281 | { |
---|
3282 | png_bytep sp; |
---|
3283 | png_uint_32 i; |
---|
3284 | png_uint_32 row_width=row_info->width; |
---|
3285 | |
---|
3286 | png_debug(1, "in png_do_gamma\n"); |
---|
3287 | if ( |
---|
3288 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
3289 | row != NULL && row_info != NULL && |
---|
3290 | #endif |
---|
3291 | ((row_info->bit_depth <= 8 && gamma_table != NULL) || |
---|
3292 | (row_info->bit_depth == 16 && gamma_16_table != NULL))) |
---|
3293 | { |
---|
3294 | switch (row_info->color_type) |
---|
3295 | { |
---|
3296 | case PNG_COLOR_TYPE_RGB: |
---|
3297 | { |
---|
3298 | if (row_info->bit_depth == 8) |
---|
3299 | { |
---|
3300 | sp = row; |
---|
3301 | for (i = 0; i < row_width; i++) |
---|
3302 | { |
---|
3303 | *sp = gamma_table[*sp]; |
---|
3304 | sp++; |
---|
3305 | *sp = gamma_table[*sp]; |
---|
3306 | sp++; |
---|
3307 | *sp = gamma_table[*sp]; |
---|
3308 | sp++; |
---|
3309 | } |
---|
3310 | } |
---|
3311 | else /* if (row_info->bit_depth == 16) */ |
---|
3312 | { |
---|
3313 | sp = row; |
---|
3314 | for (i = 0; i < row_width; i++) |
---|
3315 | { |
---|
3316 | png_uint_16 v; |
---|
3317 | |
---|
3318 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3319 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3320 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3321 | sp += 2; |
---|
3322 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3323 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3324 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3325 | sp += 2; |
---|
3326 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3327 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3328 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3329 | sp += 2; |
---|
3330 | } |
---|
3331 | } |
---|
3332 | break; |
---|
3333 | } |
---|
3334 | case PNG_COLOR_TYPE_RGB_ALPHA: |
---|
3335 | { |
---|
3336 | if (row_info->bit_depth == 8) |
---|
3337 | { |
---|
3338 | sp = row; |
---|
3339 | for (i = 0; i < row_width; i++) |
---|
3340 | { |
---|
3341 | *sp = gamma_table[*sp]; |
---|
3342 | sp++; |
---|
3343 | *sp = gamma_table[*sp]; |
---|
3344 | sp++; |
---|
3345 | *sp = gamma_table[*sp]; |
---|
3346 | sp++; |
---|
3347 | sp++; |
---|
3348 | } |
---|
3349 | } |
---|
3350 | else /* if (row_info->bit_depth == 16) */ |
---|
3351 | { |
---|
3352 | sp = row; |
---|
3353 | for (i = 0; i < row_width; i++) |
---|
3354 | { |
---|
3355 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3356 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3357 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3358 | sp += 2; |
---|
3359 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3360 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3361 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3362 | sp += 2; |
---|
3363 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3364 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3365 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3366 | sp += 4; |
---|
3367 | } |
---|
3368 | } |
---|
3369 | break; |
---|
3370 | } |
---|
3371 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
---|
3372 | { |
---|
3373 | if (row_info->bit_depth == 8) |
---|
3374 | { |
---|
3375 | sp = row; |
---|
3376 | for (i = 0; i < row_width; i++) |
---|
3377 | { |
---|
3378 | *sp = gamma_table[*sp]; |
---|
3379 | sp += 2; |
---|
3380 | } |
---|
3381 | } |
---|
3382 | else /* if (row_info->bit_depth == 16) */ |
---|
3383 | { |
---|
3384 | sp = row; |
---|
3385 | for (i = 0; i < row_width; i++) |
---|
3386 | { |
---|
3387 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3388 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3389 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3390 | sp += 4; |
---|
3391 | } |
---|
3392 | } |
---|
3393 | break; |
---|
3394 | } |
---|
3395 | case PNG_COLOR_TYPE_GRAY: |
---|
3396 | { |
---|
3397 | if (row_info->bit_depth == 2) |
---|
3398 | { |
---|
3399 | sp = row; |
---|
3400 | for (i = 0; i < row_width; i += 4) |
---|
3401 | { |
---|
3402 | int a = *sp & 0xc0; |
---|
3403 | int b = *sp & 0x30; |
---|
3404 | int c = *sp & 0x0c; |
---|
3405 | int d = *sp & 0x03; |
---|
3406 | |
---|
3407 | *sp = (png_byte)( |
---|
3408 | ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| |
---|
3409 | ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| |
---|
3410 | ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| |
---|
3411 | ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); |
---|
3412 | sp++; |
---|
3413 | } |
---|
3414 | } |
---|
3415 | if (row_info->bit_depth == 4) |
---|
3416 | { |
---|
3417 | sp = row; |
---|
3418 | for (i = 0; i < row_width; i += 2) |
---|
3419 | { |
---|
3420 | int msb = *sp & 0xf0; |
---|
3421 | int lsb = *sp & 0x0f; |
---|
3422 | |
---|
3423 | *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) |
---|
3424 | | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); |
---|
3425 | sp++; |
---|
3426 | } |
---|
3427 | } |
---|
3428 | else if (row_info->bit_depth == 8) |
---|
3429 | { |
---|
3430 | sp = row; |
---|
3431 | for (i = 0; i < row_width; i++) |
---|
3432 | { |
---|
3433 | *sp = gamma_table[*sp]; |
---|
3434 | sp++; |
---|
3435 | } |
---|
3436 | } |
---|
3437 | else if (row_info->bit_depth == 16) |
---|
3438 | { |
---|
3439 | sp = row; |
---|
3440 | for (i = 0; i < row_width; i++) |
---|
3441 | { |
---|
3442 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
---|
3443 | *sp = (png_byte)((v >> 8) & 0xff); |
---|
3444 | *(sp + 1) = (png_byte)(v & 0xff); |
---|
3445 | sp += 2; |
---|
3446 | } |
---|
3447 | } |
---|
3448 | break; |
---|
3449 | } |
---|
3450 | } |
---|
3451 | } |
---|
3452 | } |
---|
3453 | #endif |
---|
3454 | |
---|
3455 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
---|
3456 | /* Expands a palette row to an RGB or RGBA row depending |
---|
3457 | * upon whether you supply trans and num_trans. |
---|
3458 | */ |
---|
3459 | void /* PRIVATE */ |
---|
3460 | png_do_expand_palette(png_row_infop row_info, png_bytep row, |
---|
3461 | png_colorp palette, png_bytep trans, int num_trans) |
---|
3462 | { |
---|
3463 | int shift, value; |
---|
3464 | png_bytep sp, dp; |
---|
3465 | png_uint_32 i; |
---|
3466 | png_uint_32 row_width=row_info->width; |
---|
3467 | |
---|
3468 | png_debug(1, "in png_do_expand_palette\n"); |
---|
3469 | if ( |
---|
3470 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
3471 | row != NULL && row_info != NULL && |
---|
3472 | #endif |
---|
3473 | row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
3474 | { |
---|
3475 | if (row_info->bit_depth < 8) |
---|
3476 | { |
---|
3477 | switch (row_info->bit_depth) |
---|
3478 | { |
---|
3479 | case 1: |
---|
3480 | { |
---|
3481 | sp = row + (png_size_t)((row_width - 1) >> 3); |
---|
3482 | dp = row + (png_size_t)row_width - 1; |
---|
3483 | shift = 7 - (int)((row_width + 7) & 0x07); |
---|
3484 | for (i = 0; i < row_width; i++) |
---|
3485 | { |
---|
3486 | if ((*sp >> shift) & 0x01) |
---|
3487 | *dp = 1; |
---|
3488 | else |
---|
3489 | *dp = 0; |
---|
3490 | if (shift == 7) |
---|
3491 | { |
---|
3492 | shift = 0; |
---|
3493 | sp--; |
---|
3494 | } |
---|
3495 | else |
---|
3496 | shift++; |
---|
3497 | |
---|
3498 | dp--; |
---|
3499 | } |
---|
3500 | break; |
---|
3501 | } |
---|
3502 | case 2: |
---|
3503 | { |
---|
3504 | sp = row + (png_size_t)((row_width - 1) >> 2); |
---|
3505 | dp = row + (png_size_t)row_width - 1; |
---|
3506 | shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
---|
3507 | for (i = 0; i < row_width; i++) |
---|
3508 | { |
---|
3509 | value = (*sp >> shift) & 0x03; |
---|
3510 | *dp = (png_byte)value; |
---|
3511 | if (shift == 6) |
---|
3512 | { |
---|
3513 | shift = 0; |
---|
3514 | sp--; |
---|
3515 | } |
---|
3516 | else |
---|
3517 | shift += 2; |
---|
3518 | |
---|
3519 | dp--; |
---|
3520 | } |
---|
3521 | break; |
---|
3522 | } |
---|
3523 | case 4: |
---|
3524 | { |
---|
3525 | sp = row + (png_size_t)((row_width - 1) >> 1); |
---|
3526 | dp = row + (png_size_t)row_width - 1; |
---|
3527 | shift = (int)((row_width & 0x01) << 2); |
---|
3528 | for (i = 0; i < row_width; i++) |
---|
3529 | { |
---|
3530 | value = (*sp >> shift) & 0x0f; |
---|
3531 | *dp = (png_byte)value; |
---|
3532 | if (shift == 4) |
---|
3533 | { |
---|
3534 | shift = 0; |
---|
3535 | sp--; |
---|
3536 | } |
---|
3537 | else |
---|
3538 | shift += 4; |
---|
3539 | |
---|
3540 | dp--; |
---|
3541 | } |
---|
3542 | break; |
---|
3543 | } |
---|
3544 | } |
---|
3545 | row_info->bit_depth = 8; |
---|
3546 | row_info->pixel_depth = 8; |
---|
3547 | row_info->rowbytes = row_width; |
---|
3548 | } |
---|
3549 | switch (row_info->bit_depth) |
---|
3550 | { |
---|
3551 | case 8: |
---|
3552 | { |
---|
3553 | if (trans != NULL) |
---|
3554 | { |
---|
3555 | sp = row + (png_size_t)row_width - 1; |
---|
3556 | dp = row + (png_size_t)(row_width << 2) - 1; |
---|
3557 | |
---|
3558 | for (i = 0; i < row_width; i++) |
---|
3559 | { |
---|
3560 | if ((int)(*sp) >= num_trans) |
---|
3561 | *dp-- = 0xff; |
---|
3562 | else |
---|
3563 | *dp-- = trans[*sp]; |
---|
3564 | *dp-- = palette[*sp].blue; |
---|
3565 | *dp-- = palette[*sp].green; |
---|
3566 | *dp-- = palette[*sp].red; |
---|
3567 | sp--; |
---|
3568 | } |
---|
3569 | row_info->bit_depth = 8; |
---|
3570 | row_info->pixel_depth = 32; |
---|
3571 | row_info->rowbytes = row_width * 4; |
---|
3572 | row_info->color_type = 6; |
---|
3573 | row_info->channels = 4; |
---|
3574 | } |
---|
3575 | else |
---|
3576 | { |
---|
3577 | sp = row + (png_size_t)row_width - 1; |
---|
3578 | dp = row + (png_size_t)(row_width * 3) - 1; |
---|
3579 | |
---|
3580 | for (i = 0; i < row_width; i++) |
---|
3581 | { |
---|
3582 | *dp-- = palette[*sp].blue; |
---|
3583 | *dp-- = palette[*sp].green; |
---|
3584 | *dp-- = palette[*sp].red; |
---|
3585 | sp--; |
---|
3586 | } |
---|
3587 | row_info->bit_depth = 8; |
---|
3588 | row_info->pixel_depth = 24; |
---|
3589 | row_info->rowbytes = row_width * 3; |
---|
3590 | row_info->color_type = 2; |
---|
3591 | row_info->channels = 3; |
---|
3592 | } |
---|
3593 | break; |
---|
3594 | } |
---|
3595 | } |
---|
3596 | } |
---|
3597 | } |
---|
3598 | |
---|
3599 | /* If the bit depth < 8, it is expanded to 8. Also, if the |
---|
3600 | * transparency value is supplied, an alpha channel is built. |
---|
3601 | */ |
---|
3602 | void /* PRIVATE */ |
---|
3603 | png_do_expand(png_row_infop row_info, png_bytep row, |
---|
3604 | png_color_16p trans_value) |
---|
3605 | { |
---|
3606 | int shift, value; |
---|
3607 | png_bytep sp, dp; |
---|
3608 | png_uint_32 i; |
---|
3609 | png_uint_32 row_width=row_info->width; |
---|
3610 | |
---|
3611 | png_debug(1, "in png_do_expand\n"); |
---|
3612 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
3613 | if (row != NULL && row_info != NULL) |
---|
3614 | #endif |
---|
3615 | { |
---|
3616 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
---|
3617 | { |
---|
3618 | png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0); |
---|
3619 | |
---|
3620 | if (row_info->bit_depth < 8) |
---|
3621 | { |
---|
3622 | switch (row_info->bit_depth) |
---|
3623 | { |
---|
3624 | case 1: |
---|
3625 | { |
---|
3626 | gray = (png_uint_16)(gray*0xff); |
---|
3627 | sp = row + (png_size_t)((row_width - 1) >> 3); |
---|
3628 | dp = row + (png_size_t)row_width - 1; |
---|
3629 | shift = 7 - (int)((row_width + 7) & 0x07); |
---|
3630 | for (i = 0; i < row_width; i++) |
---|
3631 | { |
---|
3632 | if ((*sp >> shift) & 0x01) |
---|
3633 | *dp = 0xff; |
---|
3634 | else |
---|
3635 | *dp = 0; |
---|
3636 | if (shift == 7) |
---|
3637 | { |
---|
3638 | shift = 0; |
---|
3639 | sp--; |
---|
3640 | } |
---|
3641 | else |
---|
3642 | shift++; |
---|
3643 | |
---|
3644 | dp--; |
---|
3645 | } |
---|
3646 | break; |
---|
3647 | } |
---|
3648 | case 2: |
---|
3649 | { |
---|
3650 | gray = (png_uint_16)(gray*0x55); |
---|
3651 | sp = row + (png_size_t)((row_width - 1) >> 2); |
---|
3652 | dp = row + (png_size_t)row_width - 1; |
---|
3653 | shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
---|
3654 | for (i = 0; i < row_width; i++) |
---|
3655 | { |
---|
3656 | value = (*sp >> shift) & 0x03; |
---|
3657 | *dp = (png_byte)(value | (value << 2) | (value << 4) | |
---|
3658 | (value << 6)); |
---|
3659 | if (shift == 6) |
---|
3660 | { |
---|
3661 | shift = 0; |
---|
3662 | sp--; |
---|
3663 | } |
---|
3664 | else |
---|
3665 | shift += 2; |
---|
3666 | |
---|
3667 | dp--; |
---|
3668 | } |
---|
3669 | break; |
---|
3670 | } |
---|
3671 | case 4: |
---|
3672 | { |
---|
3673 | gray = (png_uint_16)(gray*0x11); |
---|
3674 | sp = row + (png_size_t)((row_width - 1) >> 1); |
---|
3675 | dp = row + (png_size_t)row_width - 1; |
---|
3676 | shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
---|
3677 | for (i = 0; i < row_width; i++) |
---|
3678 | { |
---|
3679 | value = (*sp >> shift) & 0x0f; |
---|
3680 | *dp = (png_byte)(value | (value << 4)); |
---|
3681 | if (shift == 4) |
---|
3682 | { |
---|
3683 | shift = 0; |
---|
3684 | sp--; |
---|
3685 | } |
---|
3686 | else |
---|
3687 | shift = 4; |
---|
3688 | |
---|
3689 | dp--; |
---|
3690 | } |
---|
3691 | break; |
---|
3692 | } |
---|
3693 | } |
---|
3694 | row_info->bit_depth = 8; |
---|
3695 | row_info->pixel_depth = 8; |
---|
3696 | row_info->rowbytes = row_width; |
---|
3697 | } |
---|
3698 | |
---|
3699 | if (trans_value != NULL) |
---|
3700 | { |
---|
3701 | if (row_info->bit_depth == 8) |
---|
3702 | { |
---|
3703 | sp = row + (png_size_t)row_width - 1; |
---|
3704 | dp = row + (png_size_t)(row_width << 1) - 1; |
---|
3705 | for (i = 0; i < row_width; i++) |
---|
3706 | { |
---|
3707 | if (*sp == gray) |
---|
3708 | *dp-- = 0; |
---|
3709 | else |
---|
3710 | *dp-- = 0xff; |
---|
3711 | *dp-- = *sp--; |
---|
3712 | } |
---|
3713 | } |
---|
3714 | else if (row_info->bit_depth == 16) |
---|
3715 | { |
---|
3716 | sp = row + row_info->rowbytes - 1; |
---|
3717 | dp = row + (row_info->rowbytes << 1) - 1; |
---|
3718 | for (i = 0; i < row_width; i++) |
---|
3719 | { |
---|
3720 | if (((png_uint_16)*(sp) | |
---|
3721 | ((png_uint_16)*(sp - 1) << 8)) == gray) |
---|
3722 | { |
---|
3723 | *dp-- = 0; |
---|
3724 | *dp-- = 0; |
---|
3725 | } |
---|
3726 | else |
---|
3727 | { |
---|
3728 | *dp-- = 0xff; |
---|
3729 | *dp-- = 0xff; |
---|
3730 | } |
---|
3731 | *dp-- = *sp--; |
---|
3732 | *dp-- = *sp--; |
---|
3733 | } |
---|
3734 | } |
---|
3735 | row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
---|
3736 | row_info->channels = 2; |
---|
3737 | row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); |
---|
3738 | row_info->rowbytes = |
---|
3739 | ((row_width * row_info->pixel_depth) >> 3); |
---|
3740 | } |
---|
3741 | } |
---|
3742 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) |
---|
3743 | { |
---|
3744 | if (row_info->bit_depth == 8) |
---|
3745 | { |
---|
3746 | sp = row + (png_size_t)row_info->rowbytes - 1; |
---|
3747 | dp = row + (png_size_t)(row_width << 2) - 1; |
---|
3748 | for (i = 0; i < row_width; i++) |
---|
3749 | { |
---|
3750 | if (*(sp - 2) == trans_value->red && |
---|
3751 | *(sp - 1) == trans_value->green && |
---|
3752 | *(sp - 0) == trans_value->blue) |
---|
3753 | *dp-- = 0; |
---|
3754 | else |
---|
3755 | *dp-- = 0xff; |
---|
3756 | *dp-- = *sp--; |
---|
3757 | *dp-- = *sp--; |
---|
3758 | *dp-- = *sp--; |
---|
3759 | } |
---|
3760 | } |
---|
3761 | else if (row_info->bit_depth == 16) |
---|
3762 | { |
---|
3763 | sp = row + row_info->rowbytes - 1; |
---|
3764 | dp = row + (png_size_t)(row_width << 3) - 1; |
---|
3765 | for (i = 0; i < row_width; i++) |
---|
3766 | { |
---|
3767 | if ((((png_uint_16)*(sp - 4) | |
---|
3768 | ((png_uint_16)*(sp - 5) << 8)) == trans_value->red) && |
---|
3769 | (((png_uint_16)*(sp - 2) | |
---|
3770 | ((png_uint_16)*(sp - 3) << 8)) == trans_value->green) && |
---|
3771 | (((png_uint_16)*(sp - 0) | |
---|
3772 | ((png_uint_16)*(sp - 1) << 8)) == trans_value->blue)) |
---|
3773 | { |
---|
3774 | *dp-- = 0; |
---|
3775 | *dp-- = 0; |
---|
3776 | } |
---|
3777 | else |
---|
3778 | { |
---|
3779 | *dp-- = 0xff; |
---|
3780 | *dp-- = 0xff; |
---|
3781 | } |
---|
3782 | *dp-- = *sp--; |
---|
3783 | *dp-- = *sp--; |
---|
3784 | *dp-- = *sp--; |
---|
3785 | *dp-- = *sp--; |
---|
3786 | *dp-- = *sp--; |
---|
3787 | *dp-- = *sp--; |
---|
3788 | } |
---|
3789 | } |
---|
3790 | row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
---|
3791 | row_info->channels = 4; |
---|
3792 | row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); |
---|
3793 | row_info->rowbytes = |
---|
3794 | ((row_width * row_info->pixel_depth) >> 3); |
---|
3795 | } |
---|
3796 | } |
---|
3797 | } |
---|
3798 | #endif |
---|
3799 | |
---|
3800 | #if defined(PNG_READ_DITHER_SUPPORTED) |
---|
3801 | void /* PRIVATE */ |
---|
3802 | png_do_dither(png_row_infop row_info, png_bytep row, |
---|
3803 | png_bytep palette_lookup, png_bytep dither_lookup) |
---|
3804 | { |
---|
3805 | png_bytep sp, dp; |
---|
3806 | png_uint_32 i; |
---|
3807 | png_uint_32 row_width=row_info->width; |
---|
3808 | |
---|
3809 | png_debug(1, "in png_do_dither\n"); |
---|
3810 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
3811 | if (row != NULL && row_info != NULL) |
---|
3812 | #endif |
---|
3813 | { |
---|
3814 | if (row_info->color_type == PNG_COLOR_TYPE_RGB && |
---|
3815 | palette_lookup && row_info->bit_depth == 8) |
---|
3816 | { |
---|
3817 | int r, g, b, p; |
---|
3818 | sp = row; |
---|
3819 | dp = row; |
---|
3820 | for (i = 0; i < row_width; i++) |
---|
3821 | { |
---|
3822 | r = *sp++; |
---|
3823 | g = *sp++; |
---|
3824 | b = *sp++; |
---|
3825 | |
---|
3826 | /* this looks real messy, but the compiler will reduce |
---|
3827 | it down to a reasonable formula. For example, with |
---|
3828 | 5 bits per color, we get: |
---|
3829 | p = (((r >> 3) & 0x1f) << 10) | |
---|
3830 | (((g >> 3) & 0x1f) << 5) | |
---|
3831 | ((b >> 3) & 0x1f); |
---|
3832 | */ |
---|
3833 | p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
---|
3834 | ((1 << PNG_DITHER_RED_BITS) - 1)) << |
---|
3835 | (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
---|
3836 | (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
---|
3837 | ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
---|
3838 | (PNG_DITHER_BLUE_BITS)) | |
---|
3839 | ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
---|
3840 | ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
---|
3841 | |
---|
3842 | *dp++ = palette_lookup[p]; |
---|
3843 | } |
---|
3844 | row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
---|
3845 | row_info->channels = 1; |
---|
3846 | row_info->pixel_depth = row_info->bit_depth; |
---|
3847 | row_info->rowbytes = |
---|
3848 | ((row_width * row_info->pixel_depth + 7) >> 3); |
---|
3849 | } |
---|
3850 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
---|
3851 | palette_lookup != NULL && row_info->bit_depth == 8) |
---|
3852 | { |
---|
3853 | int r, g, b, p; |
---|
3854 | sp = row; |
---|
3855 | dp = row; |
---|
3856 | for (i = 0; i < row_width; i++) |
---|
3857 | { |
---|
3858 | r = *sp++; |
---|
3859 | g = *sp++; |
---|
3860 | b = *sp++; |
---|
3861 | sp++; |
---|
3862 | |
---|
3863 | p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
---|
3864 | ((1 << PNG_DITHER_RED_BITS) - 1)) << |
---|
3865 | (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
---|
3866 | (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
---|
3867 | ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
---|
3868 | (PNG_DITHER_BLUE_BITS)) | |
---|
3869 | ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
---|
3870 | ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
---|
3871 | |
---|
3872 | *dp++ = palette_lookup[p]; |
---|
3873 | } |
---|
3874 | row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
---|
3875 | row_info->channels = 1; |
---|
3876 | row_info->pixel_depth = row_info->bit_depth; |
---|
3877 | row_info->rowbytes = |
---|
3878 | ((row_width * row_info->pixel_depth + 7) >> 3); |
---|
3879 | } |
---|
3880 | else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
---|
3881 | dither_lookup && row_info->bit_depth == 8) |
---|
3882 | { |
---|
3883 | sp = row; |
---|
3884 | for (i = 0; i < row_width; i++, sp++) |
---|
3885 | { |
---|
3886 | *sp = dither_lookup[*sp]; |
---|
3887 | } |
---|
3888 | } |
---|
3889 | } |
---|
3890 | } |
---|
3891 | #endif |
---|
3892 | |
---|
3893 | #ifdef PNG_FLOATING_POINT_SUPPORTED |
---|
3894 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
---|
3895 | static int png_gamma_shift[] = |
---|
3896 | {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0}; |
---|
3897 | |
---|
3898 | /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit |
---|
3899 | * tables, we don't make a full table if we are reducing to 8-bit in |
---|
3900 | * the future. Note also how the gamma_16 tables are segmented so that |
---|
3901 | * we don't need to allocate > 64K chunks for a full 16-bit table. |
---|
3902 | */ |
---|
3903 | void /* PRIVATE */ |
---|
3904 | png_build_gamma_table(png_structp png_ptr) |
---|
3905 | { |
---|
3906 | png_debug(1, "in png_build_gamma_table\n"); |
---|
3907 | if(png_ptr->gamma != 0.0) |
---|
3908 | { |
---|
3909 | if (png_ptr->bit_depth <= 8) |
---|
3910 | { |
---|
3911 | int i; |
---|
3912 | double g; |
---|
3913 | |
---|
3914 | if (png_ptr->screen_gamma > .000001) |
---|
3915 | g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
---|
3916 | else |
---|
3917 | g = 1.0; |
---|
3918 | |
---|
3919 | png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, |
---|
3920 | (png_uint_32)256); |
---|
3921 | |
---|
3922 | for (i = 0; i < 256; i++) |
---|
3923 | { |
---|
3924 | png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0, |
---|
3925 | g) * 255.0 + .5); |
---|
3926 | } |
---|
3927 | |
---|
3928 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
---|
3929 | defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
---|
3930 | if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY)) |
---|
3931 | { |
---|
3932 | |
---|
3933 | g = 1.0 / (png_ptr->gamma); |
---|
3934 | |
---|
3935 | png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr, |
---|
3936 | (png_uint_32)256); |
---|
3937 | |
---|
3938 | for (i = 0; i < 256; i++) |
---|
3939 | { |
---|
3940 | png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0, |
---|
3941 | g) * 255.0 + .5); |
---|
3942 | } |
---|
3943 | |
---|
3944 | |
---|
3945 | png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, |
---|
3946 | (png_uint_32)256); |
---|
3947 | |
---|
3948 | if(png_ptr->screen_gamma > 0.000001) |
---|
3949 | g = 1.0 / png_ptr->screen_gamma; |
---|
3950 | else |
---|
3951 | g = png_ptr->gamma; /* probably doing rgb_to_gray */ |
---|
3952 | |
---|
3953 | for (i = 0; i < 256; i++) |
---|
3954 | { |
---|
3955 | png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0, |
---|
3956 | g) * 255.0 + .5); |
---|
3957 | |
---|
3958 | } |
---|
3959 | } |
---|
3960 | #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
---|
3961 | } |
---|
3962 | else |
---|
3963 | { |
---|
3964 | double g; |
---|
3965 | int i, j, shift, num; |
---|
3966 | int sig_bit; |
---|
3967 | png_uint_32 ig; |
---|
3968 | |
---|
3969 | if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
---|
3970 | { |
---|
3971 | sig_bit = (int)png_ptr->sig_bit.red; |
---|
3972 | if ((int)png_ptr->sig_bit.green > sig_bit) |
---|
3973 | sig_bit = png_ptr->sig_bit.green; |
---|
3974 | if ((int)png_ptr->sig_bit.blue > sig_bit) |
---|
3975 | sig_bit = png_ptr->sig_bit.blue; |
---|
3976 | } |
---|
3977 | else |
---|
3978 | { |
---|
3979 | sig_bit = (int)png_ptr->sig_bit.gray; |
---|
3980 | } |
---|
3981 | |
---|
3982 | if (sig_bit > 0) |
---|
3983 | shift = 16 - sig_bit; |
---|
3984 | else |
---|
3985 | shift = 0; |
---|
3986 | |
---|
3987 | if (png_ptr->transformations & PNG_16_TO_8) |
---|
3988 | { |
---|
3989 | if (shift < (16 - PNG_MAX_GAMMA_8)) |
---|
3990 | shift = (16 - PNG_MAX_GAMMA_8); |
---|
3991 | } |
---|
3992 | |
---|
3993 | if (shift > 8) |
---|
3994 | shift = 8; |
---|
3995 | if (shift < 0) |
---|
3996 | shift = 0; |
---|
3997 | |
---|
3998 | png_ptr->gamma_shift = (png_byte)shift; |
---|
3999 | |
---|
4000 | num = (1 << (8 - shift)); |
---|
4001 | |
---|
4002 | if (png_ptr->screen_gamma > .000001) |
---|
4003 | g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
---|
4004 | else |
---|
4005 | g = 1.0; |
---|
4006 | |
---|
4007 | png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr, |
---|
4008 | (png_uint_32)(num * sizeof (png_uint_16p))); |
---|
4009 | |
---|
4010 | if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) |
---|
4011 | { |
---|
4012 | double fin, fout; |
---|
4013 | png_uint_32 last, max; |
---|
4014 | |
---|
4015 | for (i = 0; i < num; i++) |
---|
4016 | { |
---|
4017 | png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
---|
4018 | (png_uint_32)(256 * sizeof (png_uint_16))); |
---|
4019 | } |
---|
4020 | |
---|
4021 | g = 1.0 / g; |
---|
4022 | last = 0; |
---|
4023 | for (i = 0; i < 256; i++) |
---|
4024 | { |
---|
4025 | fout = ((double)i + 0.5) / 256.0; |
---|
4026 | fin = pow(fout, g); |
---|
4027 | max = (png_uint_32)(fin * (double)((png_uint_32)num << 8)); |
---|
4028 | while (last <= max) |
---|
4029 | { |
---|
4030 | png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
---|
4031 | [(int)(last >> (8 - shift))] = (png_uint_16)( |
---|
4032 | (png_uint_16)i | ((png_uint_16)i << 8)); |
---|
4033 | last++; |
---|
4034 | } |
---|
4035 | } |
---|
4036 | while (last < ((png_uint_32)num << 8)) |
---|
4037 | { |
---|
4038 | png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
---|
4039 | [(int)(last >> (8 - shift))] = (png_uint_16)65535L; |
---|
4040 | last++; |
---|
4041 | } |
---|
4042 | } |
---|
4043 | else |
---|
4044 | { |
---|
4045 | for (i = 0; i < num; i++) |
---|
4046 | { |
---|
4047 | png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
---|
4048 | (png_uint_32)(256 * sizeof (png_uint_16))); |
---|
4049 | |
---|
4050 | ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4); |
---|
4051 | for (j = 0; j < 256; j++) |
---|
4052 | { |
---|
4053 | png_ptr->gamma_16_table[i][j] = |
---|
4054 | (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
---|
4055 | 65535.0, g) * 65535.0 + .5); |
---|
4056 | } |
---|
4057 | } |
---|
4058 | } |
---|
4059 | |
---|
4060 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
---|
4061 | defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
---|
4062 | if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) |
---|
4063 | { |
---|
4064 | |
---|
4065 | g = 1.0 / (png_ptr->gamma); |
---|
4066 | |
---|
4067 | png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr, |
---|
4068 | (png_uint_32)(num * sizeof (png_uint_16p ))); |
---|
4069 | |
---|
4070 | for (i = 0; i < num; i++) |
---|
4071 | { |
---|
4072 | png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr, |
---|
4073 | (png_uint_32)(256 * sizeof (png_uint_16))); |
---|
4074 | |
---|
4075 | ig = (((png_uint_32)i * |
---|
4076 | (png_uint_32)png_gamma_shift[shift]) >> 4); |
---|
4077 | for (j = 0; j < 256; j++) |
---|
4078 | { |
---|
4079 | png_ptr->gamma_16_to_1[i][j] = |
---|
4080 | (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
---|
4081 | 65535.0, g) * 65535.0 + .5); |
---|
4082 | } |
---|
4083 | } |
---|
4084 | |
---|
4085 | if(png_ptr->screen_gamma > 0.000001) |
---|
4086 | g = 1.0 / png_ptr->screen_gamma; |
---|
4087 | else |
---|
4088 | g = png_ptr->gamma; /* probably doing rgb_to_gray */ |
---|
4089 | |
---|
4090 | png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr, |
---|
4091 | (png_uint_32)(num * sizeof (png_uint_16p))); |
---|
4092 | |
---|
4093 | for (i = 0; i < num; i++) |
---|
4094 | { |
---|
4095 | png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr, |
---|
4096 | (png_uint_32)(256 * sizeof (png_uint_16))); |
---|
4097 | |
---|
4098 | ig = (((png_uint_32)i * |
---|
4099 | (png_uint_32)png_gamma_shift[shift]) >> 4); |
---|
4100 | for (j = 0; j < 256; j++) |
---|
4101 | { |
---|
4102 | png_ptr->gamma_16_from_1[i][j] = |
---|
4103 | (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
---|
4104 | 65535.0, g) * 65535.0 + .5); |
---|
4105 | } |
---|
4106 | } |
---|
4107 | } |
---|
4108 | #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
---|
4109 | } |
---|
4110 | } |
---|
4111 | } |
---|
4112 | #endif |
---|
4113 | /* To do: install integer version of png_build_gamma_table here */ |
---|
4114 | #endif |
---|
4115 | |
---|
4116 | #if defined(PNG_MNG_FEATURES_SUPPORTED) |
---|
4117 | /* undoes intrapixel differencing */ |
---|
4118 | void /* PRIVATE */ |
---|
4119 | png_do_read_intrapixel(png_row_infop row_info, png_bytep row) |
---|
4120 | { |
---|
4121 | png_debug(1, "in png_do_read_intrapixel\n"); |
---|
4122 | if ( |
---|
4123 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
---|
4124 | row != NULL && row_info != NULL && |
---|
4125 | #endif |
---|
4126 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
---|
4127 | { |
---|
4128 | int bytes_per_pixel; |
---|
4129 | png_uint_32 row_width = row_info->width; |
---|
4130 | if (row_info->bit_depth == 8) |
---|
4131 | { |
---|
4132 | png_bytep rp; |
---|
4133 | png_uint_32 i; |
---|
4134 | |
---|
4135 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
---|
4136 | bytes_per_pixel = 3; |
---|
4137 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
---|
4138 | bytes_per_pixel = 4; |
---|
4139 | else |
---|
4140 | return; |
---|
4141 | |
---|
4142 | for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
---|
4143 | { |
---|
4144 | *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff); |
---|
4145 | *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff); |
---|
4146 | } |
---|
4147 | } |
---|
4148 | else if (row_info->bit_depth == 16) |
---|
4149 | { |
---|
4150 | png_bytep rp; |
---|
4151 | png_uint_32 i; |
---|
4152 | |
---|
4153 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
---|
4154 | bytes_per_pixel = 6; |
---|
4155 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
---|
4156 | bytes_per_pixel = 8; |
---|
4157 | else |
---|
4158 | return; |
---|
4159 | |
---|
4160 | for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
---|
4161 | { |
---|
4162 | png_uint_32 s0=*(rp )<<8 | *(rp+1); |
---|
4163 | png_uint_32 s1=*(rp+2)<<8 | *(rp+3); |
---|
4164 | png_uint_32 s2=*(rp+4)<<8 | *(rp+5); |
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4165 | png_uint_32 red=(65536+s0+s1)&0xffff; |
---|
4166 | png_uint_32 blue=(65536+s2+s1)&0xffff; |
---|
4167 | *(rp ) = (png_byte)((red>>8)&0xff); |
---|
4168 | *(rp+1) = (png_byte)(red&0xff); |
---|
4169 | *(rp+4) = (png_byte)((blue>>8)&0xff); |
---|
4170 | *(rp+5) = (png_byte)(blue&0xff); |
---|
4171 | } |
---|
4172 | } |
---|
4173 | } |
---|
4174 | } |
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4175 | #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
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