1 | /* |
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2 | * png2pnm.c --- conversion from PNG-file to PGM/PPM-file |
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3 | * copyright (C) 1999 by Willem van Schaik <willem@schaik.com> |
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4 | * |
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5 | * version 1.0 - 1999.10.15 - First version. |
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6 | * |
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7 | * Permission to use, copy, modify, and distribute this software and |
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8 | * its documentation for any purpose and without fee is hereby granted, |
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9 | * provided that the above copyright notice appear in all copies and |
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10 | * that both that copyright notice and this permission notice appear in |
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11 | * supporting documentation. This software is provided "as is" without |
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12 | * express or implied warranty. |
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13 | */ |
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14 | |
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15 | #include <stdio.h> |
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16 | #include <stdlib.h> |
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17 | #ifdef __TURBOC__ |
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18 | #include <mem.h> |
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19 | #include <fcntl.h> |
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20 | #endif |
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21 | |
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22 | #ifndef BOOL |
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23 | #define BOOL unsigned char |
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24 | #endif |
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25 | #ifndef TRUE |
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26 | #define TRUE (BOOL) 1 |
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27 | #endif |
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28 | #ifndef FALSE |
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29 | #define FALSE (BOOL) 0 |
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30 | #endif |
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31 | |
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32 | #ifdef __TURBOC__ |
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33 | #define STDIN 0 |
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34 | #define STDOUT 1 |
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35 | #define STDERR 2 |
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36 | #endif |
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37 | |
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38 | /* to make png2pnm verbose so we can find problems (needs to be before png.h) */ |
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39 | #ifndef PNG_DEBUG |
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40 | #define PNG_DEBUG 0 |
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41 | #endif |
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42 | |
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43 | #include "png.h" |
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44 | |
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45 | /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */ |
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46 | #ifndef png_jmpbuf |
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47 | # define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf) |
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48 | #endif |
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49 | |
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50 | /* function prototypes */ |
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51 | |
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52 | int main (int argc, char *argv[]); |
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53 | void usage (); |
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54 | BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha); |
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55 | |
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56 | /* |
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57 | * main |
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58 | */ |
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59 | |
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60 | int main(int argc, char *argv[]) |
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61 | { |
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62 | FILE *fp_rd = stdin; |
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63 | FILE *fp_wr = stdout; |
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64 | FILE *fp_al = NULL; |
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65 | BOOL raw = TRUE; |
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66 | BOOL alpha = FALSE; |
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67 | int argi; |
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68 | |
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69 | for (argi = 1; argi < argc; argi++) |
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70 | { |
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71 | if (argv[argi][0] == '-') |
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72 | { |
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73 | switch (argv[argi][1]) |
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74 | { |
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75 | case 'n': |
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76 | raw = FALSE; |
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77 | break; |
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78 | case 'r': |
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79 | raw = TRUE; |
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80 | break; |
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81 | case 'a': |
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82 | alpha = TRUE; |
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83 | argi++; |
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84 | if ((fp_al = fopen (argv[argi], "wb")) == NULL) |
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85 | { |
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86 | fprintf (stderr, "PNM2PNG\n"); |
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87 | fprintf (stderr, "Error: can not create alpha-channel file %s\n", argv[argi]); |
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88 | exit (1); |
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89 | } |
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90 | break; |
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91 | case 'h': |
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92 | case '?': |
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93 | usage(); |
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94 | exit(0); |
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95 | break; |
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96 | default: |
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97 | fprintf (stderr, "PNG2PNM\n"); |
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98 | fprintf (stderr, "Error: unknown option %s\n", argv[argi]); |
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99 | usage(); |
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100 | exit(1); |
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101 | break; |
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102 | } /* end switch */ |
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103 | } |
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104 | else if (fp_rd == stdin) |
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105 | { |
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106 | if ((fp_rd = fopen (argv[argi], "rb")) == NULL) |
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107 | { |
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108 | fprintf (stderr, "PNG2PNM\n"); |
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109 | fprintf (stderr, "Error: file %s does not exist\n", argv[argi]); |
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110 | exit (1); |
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111 | } |
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112 | } |
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113 | else if (fp_wr == stdout) |
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114 | { |
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115 | if ((fp_wr = fopen (argv[argi], "wb")) == NULL) |
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116 | { |
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117 | fprintf (stderr, "PNG2PNM\n"); |
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118 | fprintf (stderr, "Error: can not create file %s\n", argv[argi]); |
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119 | exit (1); |
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120 | } |
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121 | } |
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122 | else |
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123 | { |
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124 | fprintf (stderr, "PNG2PNM\n"); |
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125 | fprintf (stderr, "Error: too many parameters\n"); |
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126 | usage(); |
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127 | exit(1); |
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128 | } |
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129 | } /* end for */ |
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130 | |
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131 | #ifdef __TURBOC__ |
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132 | /* set stdin/stdout if required to binary */ |
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133 | if (fp_rd == stdin) |
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134 | { |
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135 | setmode (STDIN, O_BINARY); |
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136 | } |
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137 | if ((raw) && (fp_wr == stdout)) |
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138 | { |
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139 | setmode (STDOUT, O_BINARY); |
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140 | } |
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141 | #endif |
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142 | |
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143 | /* call the conversion program itself */ |
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144 | if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE) |
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145 | { |
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146 | fprintf (stderr, "PNG2PNM\n"); |
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147 | fprintf (stderr, "Error: unsuccessful conversion of PNG-image\n"); |
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148 | exit(1); |
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149 | } |
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150 | |
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151 | /* close input file */ |
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152 | fclose (fp_rd); |
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153 | /* close output file */ |
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154 | fclose (fp_wr); |
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155 | /* close alpha file */ |
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156 | if (alpha) |
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157 | fclose (fp_al); |
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158 | |
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159 | return 0; |
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160 | } |
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161 | |
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162 | /* |
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163 | * usage |
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164 | */ |
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165 | |
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166 | void usage() |
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167 | { |
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168 | fprintf (stderr, "PNG2PNM\n"); |
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169 | fprintf (stderr, " by Willem van Schaik, 1999\n"); |
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170 | #ifdef __TURBOC__ |
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171 | fprintf (stderr, " for Turbo-C and Borland-C compilers\n"); |
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172 | #else |
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173 | fprintf (stderr, " for Linux (and Unix) compilers\n"); |
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174 | #endif |
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175 | fprintf (stderr, "Usage: png2pnm [options] <file>.png [<file>.pnm]\n"); |
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176 | fprintf (stderr, " or: ... | png2pnm [options]\n"); |
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177 | fprintf (stderr, "Options:\n"); |
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178 | fprintf (stderr, " -r[aw] write pnm-file in binary format (P4/P5/P6) (default)\n"); |
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179 | fprintf (stderr, " -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n"); |
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180 | fprintf (stderr, " -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n"); |
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181 | fprintf (stderr, " -h | -? print this help-information\n"); |
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182 | } |
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183 | |
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184 | /* |
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185 | * png2pnm |
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186 | */ |
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187 | |
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188 | BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha) |
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189 | { |
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190 | png_struct *png_ptr = NULL; |
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191 | png_info *info_ptr = NULL; |
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192 | png_byte buf[8]; |
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193 | png_byte *png_pixels = NULL; |
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194 | png_byte **row_pointers = NULL; |
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195 | png_byte *pix_ptr = NULL; |
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196 | png_uint_32 row_bytes; |
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197 | |
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198 | png_uint_32 width; |
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199 | png_uint_32 height; |
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200 | int bit_depth; |
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201 | int channels; |
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202 | int color_type; |
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203 | int alpha_present; |
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204 | int row, col; |
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205 | int ret; |
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206 | int i; |
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207 | long dep_16; |
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208 | |
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209 | /* read and check signature in PNG file */ |
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210 | ret = fread (buf, 1, 8, png_file); |
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211 | if (ret != 8) |
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212 | return FALSE; |
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213 | |
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214 | ret = png_sig_cmp (buf, 0, 8); |
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215 | if (ret) |
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216 | return FALSE; |
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217 | |
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218 | /* create png and info structures */ |
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219 | |
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220 | png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, |
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221 | NULL, NULL, NULL); |
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222 | if (!png_ptr) |
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223 | return FALSE; /* out of memory */ |
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224 | |
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225 | info_ptr = png_create_info_struct (png_ptr); |
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226 | if (!info_ptr) |
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227 | { |
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228 | png_destroy_read_struct (&png_ptr, NULL, NULL); |
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229 | return FALSE; /* out of memory */ |
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230 | } |
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231 | |
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232 | if (setjmp (png_jmpbuf(png_ptr))) |
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233 | { |
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234 | png_destroy_read_struct (&png_ptr, &info_ptr, NULL); |
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235 | return FALSE; |
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236 | } |
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237 | |
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238 | /* set up the input control for C streams */ |
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239 | png_init_io (png_ptr, png_file); |
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240 | png_set_sig_bytes (png_ptr, 8); /* we already read the 8 signature bytes */ |
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241 | |
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242 | /* read the file information */ |
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243 | png_read_info (png_ptr, info_ptr); |
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244 | |
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245 | /* get size and bit-depth of the PNG-image */ |
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246 | png_get_IHDR (png_ptr, info_ptr, |
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247 | &width, &height, &bit_depth, &color_type, |
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248 | NULL, NULL, NULL); |
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249 | |
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250 | /* set-up the transformations */ |
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251 | |
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252 | /* transform paletted images into full-color rgb */ |
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253 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
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254 | png_set_expand (png_ptr); |
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255 | /* expand images to bit-depth 8 (only applicable for grayscale images) */ |
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256 | if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) |
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257 | png_set_expand (png_ptr); |
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258 | /* transform transparency maps into full alpha-channel */ |
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259 | if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS)) |
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260 | png_set_expand (png_ptr); |
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261 | |
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262 | #ifdef NJET |
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263 | /* downgrade 16-bit images to 8 bit */ |
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264 | if (bit_depth == 16) |
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265 | png_set_strip_16 (png_ptr); |
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266 | /* transform grayscale images into full-color */ |
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267 | if (color_type == PNG_COLOR_TYPE_GRAY || |
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268 | color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
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269 | png_set_gray_to_rgb (png_ptr); |
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270 | /* only if file has a file gamma, we do a correction */ |
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271 | if (png_get_gAMA (png_ptr, info_ptr, &file_gamma)) |
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272 | png_set_gamma (png_ptr, (double) 2.2, file_gamma); |
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273 | #endif |
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274 | |
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275 | /* all transformations have been registered; now update info_ptr data, |
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276 | * get rowbytes and channels, and allocate image memory */ |
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277 | |
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278 | png_read_update_info (png_ptr, info_ptr); |
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279 | |
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280 | /* get the new color-type and bit-depth (after expansion/stripping) */ |
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281 | png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, |
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282 | NULL, NULL, NULL); |
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283 | |
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284 | /* check for 16-bit files */ |
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285 | if (bit_depth == 16) |
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286 | { |
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287 | raw = FALSE; |
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288 | #ifdef __TURBOC__ |
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289 | pnm_file->flags &= ~((unsigned) _F_BIN); |
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290 | #endif |
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291 | } |
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292 | |
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293 | /* calculate new number of channels and store alpha-presence */ |
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294 | if (color_type == PNG_COLOR_TYPE_GRAY) |
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295 | channels = 1; |
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296 | else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
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297 | channels = 2; |
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298 | else if (color_type == PNG_COLOR_TYPE_RGB) |
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299 | channels = 3; |
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300 | else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
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301 | channels = 4; |
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302 | else |
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303 | channels = 0; /* should never happen */ |
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304 | alpha_present = (channels - 1) % 2; |
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305 | |
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306 | /* check if alpha is expected to be present in file */ |
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307 | if (alpha && !alpha_present) |
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308 | { |
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309 | fprintf (stderr, "PNG2PNM\n"); |
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310 | fprintf (stderr, "Error: PNG-file doesn't contain alpha channel\n"); |
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311 | exit (1); |
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312 | } |
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313 | |
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314 | /* row_bytes is the width x number of channels x (bit-depth / 8) */ |
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315 | row_bytes = png_get_rowbytes (png_ptr, info_ptr); |
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316 | |
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317 | if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) { |
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318 | png_destroy_read_struct (&png_ptr, &info_ptr, NULL); |
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319 | return FALSE; |
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320 | } |
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321 | |
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322 | if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL) |
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323 | { |
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324 | png_destroy_read_struct (&png_ptr, &info_ptr, NULL); |
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325 | free (png_pixels); |
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326 | png_pixels = NULL; |
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327 | return FALSE; |
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328 | } |
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329 | |
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330 | /* set the individual row_pointers to point at the correct offsets */ |
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331 | for (i = 0; i < (height); i++) |
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332 | row_pointers[i] = png_pixels + i * row_bytes; |
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333 | |
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334 | /* now we can go ahead and just read the whole image */ |
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335 | png_read_image (png_ptr, row_pointers); |
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336 | |
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337 | /* read rest of file, and get additional chunks in info_ptr - REQUIRED */ |
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338 | png_read_end (png_ptr, info_ptr); |
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339 | |
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340 | /* clean up after the read, and free any memory allocated - REQUIRED */ |
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341 | png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL); |
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342 | |
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343 | /* write header of PNM file */ |
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344 | |
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345 | if ((color_type == PNG_COLOR_TYPE_GRAY) || |
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346 | (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) |
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347 | { |
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348 | fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2"); |
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349 | fprintf (pnm_file, "%d %d\n", (int) width, (int) height); |
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350 | fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L)); |
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351 | } |
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352 | else if ((color_type == PNG_COLOR_TYPE_RGB) || |
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353 | (color_type == PNG_COLOR_TYPE_RGB_ALPHA)) |
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354 | { |
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355 | fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3"); |
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356 | fprintf (pnm_file, "%d %d\n", (int) width, (int) height); |
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357 | fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L)); |
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358 | } |
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359 | |
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360 | /* write header of PGM file with alpha channel */ |
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361 | |
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362 | if ((alpha) && |
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363 | ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) || |
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364 | (color_type == PNG_COLOR_TYPE_RGB_ALPHA))) |
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365 | { |
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366 | fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2"); |
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367 | fprintf (alpha_file, "%d %d\n", (int) width, (int) height); |
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368 | fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L)); |
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369 | } |
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370 | |
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371 | /* write data to PNM file */ |
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372 | pix_ptr = png_pixels; |
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373 | |
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374 | for (row = 0; row < height; row++) |
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375 | { |
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376 | for (col = 0; col < width; col++) |
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377 | { |
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378 | for (i = 0; i < (channels - alpha_present); i++) |
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379 | { |
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380 | if (raw) |
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381 | fputc ((int) *pix_ptr++ , pnm_file); |
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382 | else |
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383 | if (bit_depth == 16){ |
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384 | dep_16 = (long) *pix_ptr++; |
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385 | fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++)); |
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386 | } |
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387 | else |
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388 | fprintf (pnm_file, "%ld ", (long) *pix_ptr++); |
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389 | } |
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390 | if (alpha_present) |
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391 | { |
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392 | if (!alpha) |
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393 | { |
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394 | pix_ptr++; /* alpha */ |
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395 | if (bit_depth == 16) |
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396 | pix_ptr++; |
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397 | } |
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398 | else /* output alpha-channel as pgm file */ |
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399 | { |
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400 | if (raw) |
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401 | fputc ((int) *pix_ptr++ , alpha_file); |
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402 | else |
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403 | if (bit_depth == 16){ |
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404 | dep_16 = (long) *pix_ptr++; |
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405 | fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++); |
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406 | } |
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407 | else |
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408 | fprintf (alpha_file, "%ld ", (long) *pix_ptr++); |
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409 | } |
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410 | } /* if alpha_present */ |
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411 | |
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412 | if (!raw) |
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413 | if (col % 4 == 3) |
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414 | fprintf (pnm_file, "\n"); |
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415 | } /* end for col */ |
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416 | |
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417 | if (!raw) |
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418 | if (col % 4 != 0) |
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419 | fprintf (pnm_file, "\n"); |
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420 | } /* end for row */ |
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421 | |
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422 | if (row_pointers != (unsigned char**) NULL) |
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423 | free (row_pointers); |
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424 | if (png_pixels != (unsigned char*) NULL) |
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425 | free (png_pixels); |
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426 | |
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427 | return TRUE; |
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428 | |
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429 | } /* end of source */ |
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430 | |
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