source/libs/libpng/libpng-src/contrib/pngminus/png2pnm.c

   1 /*
   2  *  png2pnm.c --- conversion from PNG-file to PGM/PPM-file
   3  *  copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
   4  *
   5  *  version 1.0 - 1999.10.15 - First version.
   6  *
   7  *  Permission to use, copy, modify, and distribute this software and
   8  *  its documentation for any purpose and without fee is hereby granted,
   9  *  provided that the above copyright notice appear in all copies and
  10  *  that both that copyright notice and this permission notice appear in
  11  *  supporting documentation. This software is provided "as is" without
  12  *  express or implied warranty.
  13  */
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #ifdef __TURBOC__
  18 #include <mem.h>
  19 #include <fcntl.h>
  20 #endif
  21 #include <zlib.h>
  22
  23 #ifndef BOOL
  24 #define BOOL unsigned char
  25 #endif
  26 #ifndef TRUE
  27 #define TRUE (BOOL) 1
  28 #endif
  29 #ifndef FALSE
  30 #define FALSE (BOOL) 0
  31 #endif
  32
  33 #ifdef __TURBOC__
  34 #define STDIN  0
  35 #define STDOUT 1
  36 #define STDERR 2
  37 #endif
  38
  39 /* to make png2pnm verbose so we can find problems (needs to be before png.h) */
  40 #ifndef PNG_DEBUG
  41 #define PNG_DEBUG 0
  42 #endif
  43
  44 #include "png.h"
  45
  46 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
  47 #ifndef png_jmpbuf
  48 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
  49 #endif
  50
  51 /* function prototypes */
  52
  53 int  main (int argc, char *argv[]);
  54 void usage ();
  55 BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw,
  56    BOOL alpha);
  57
  58 /*
  59  *  main
  60  */
  61
  62 int main(int argc, char *argv[])
  63 {
  64   FILE *fp_rd = stdin;
  65   FILE *fp_wr = stdout;
  66   FILE *fp_al = NULL;
  67   BOOL raw = TRUE;
  68   BOOL alpha = FALSE;
  69   int argi;
  70
  71   for (argi = 1; argi < argc; argi++)
  72   {
  73     if (argv[argi][0] == '-')
  74     {
  75       switch (argv[argi][1])
  76       {
  77         case 'n':
  78           raw = FALSE;
  79           break;
  80         case 'r':
  81           raw = TRUE;
  82           break;
  83         case 'a':
  84           alpha = TRUE;
  85           argi++;
  86           if ((fp_al = fopen (argv[argi], "wb")) == NULL)
  87           {
  88             fprintf (stderr, "PNM2PNG\n");
  89             fprintf (stderr, "Error:  can not create alpha-channel file %s\n",
  90                argv[argi]);
  91             exit (1);
  92           }
  93           break;
  94         case 'h':
  95         case '?':
  96           usage();
  97           exit(0);
  98           break;
  99         default:
 100           fprintf (stderr, "PNG2PNM\n");
 101           fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
 102           usage();
 103           exit(1);
 104           break;
 105       } /* end switch */
 106     }
 107     else if (fp_rd == stdin)
 108     {
 109       if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
 110       {
 111              fprintf (stderr, "PNG2PNM\n");
 112             fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
 113             exit (1);
 114       }
 115     }
 116     else if (fp_wr == stdout)
 117     {
 118       if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
 119       {
 120         fprintf (stderr, "PNG2PNM\n");
 121         fprintf (stderr, "Error:  can not create file %s\n", argv[argi]);
 122         exit (1);
 123       }
 124     }
 125     else
 126     {
 127       fprintf (stderr, "PNG2PNM\n");
 128       fprintf (stderr, "Error:  too many parameters\n");
 129       usage();
 130       exit(1);
 131     }
 132   } /* end for */
 133
 134 #ifdef __TURBOC__
 135   /* set stdin/stdout if required to binary */
 136   if (fp_rd == stdin)
 137   {
 138     setmode (STDIN, O_BINARY);
 139   }
 140   if ((raw) && (fp_wr == stdout))
 141   {
 142     setmode (STDOUT, O_BINARY);
 143   }
 144 #endif
 145
 146   /* call the conversion program itself */
 147   if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
 148   {
 149     fprintf (stderr, "PNG2PNM\n");
 150     fprintf (stderr, "Error:  unsuccessful conversion of PNG-image\n");
 151     exit(1);
 152   }
 153
 154   /* close input file */
 155   fclose (fp_rd);
 156   /* close output file */
 157   fclose (fp_wr);
 158   /* close alpha file */
 159   if (alpha)
 160     fclose (fp_al);
 161
 162   return 0;
 163 }
 164
 165 /*
 166  *  usage
 167  */
 168
 169 void usage()
 170 {
 171   fprintf (stderr, "PNG2PNM\n");
 172   fprintf (stderr, "   by Willem van Schaik, 1999\n");
 173 #ifdef __TURBOC__
 174   fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
 175 #else
 176   fprintf (stderr, "   for Linux (and Unix) compilers\n");
 177 #endif
 178   fprintf (stderr, "Usage:  png2pnm [options] <file>.png [<file>.pnm]\n");
 179   fprintf (stderr, "   or:  ... | png2pnm [options]\n");
 180   fprintf (stderr, "Options:\n");
 181   fprintf (stderr,
 182      "   -r[aw]   write pnm-file in binary format (P4/P5/P6) (default)\n");
 183   fprintf (stderr, "   -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
 184   fprintf (stderr,
 185      "   -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
 186   fprintf (stderr, "   -h | -?  print this help-information\n");
 187 }
 188
 189 /*
 190  *  png2pnm
 191  */
 192
 193 BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file,
 194     volatile BOOL raw, BOOL alpha)
 195 {
 196   png_struct    *png_ptr = NULL;
 197   png_info        *info_ptr = NULL;
 198   png_byte      buf[8];
 199   png_byte      *png_pixels = NULL;
 200   png_byte      **row_pointers = NULL;
 201   png_byte      *pix_ptr = NULL;
 202   png_uint_32   row_bytes;
 203
 204   png_uint_32   width;
 205   png_uint_32   height;
 206   int           bit_depth;
 207   int           channels;
 208   int           color_type;
 209   int           alpha_present;
 210   int           row, col;
 211   int           ret;
 212   int           i;
 213   long          dep_16;
 214
 215   /* read and check signature in PNG file */
 216   ret = fread (buf, 1, 8, png_file);
 217   if (ret != 8)
 218     return FALSE;
 219
 220   ret = png_sig_cmp (buf, 0, 8);
 221   if (ret)
 222     return FALSE;
 223
 224   /* create png and info structures */
 225
 226   png_ptr = png_create_read_struct (png_get_libpng_ver(NULL),
 227     NULL, NULL, NULL);
 228   if (!png_ptr)
 229     return FALSE;   /* out of memory */
 230
 231   info_ptr = png_create_info_struct (png_ptr);
 232   if (!info_ptr)
 233   {
 234     png_destroy_read_struct (&png_ptr, NULL, NULL);
 235     return FALSE;   /* out of memory */
 236   }
 237
 238   if (setjmp (png_jmpbuf(png_ptr)))
 239   {
 240     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
 241     return FALSE;
 242   }
 243
 244   /* set up the input control for C streams */
 245   png_init_io (png_ptr, png_file);
 246   png_set_sig_bytes (png_ptr, 8);  /* we already read the 8 signature bytes */
 247
 248   /* read the file information */
 249   png_read_info (png_ptr, info_ptr);
 250
 251   /* get size and bit-depth of the PNG-image */
 252   png_get_IHDR (png_ptr, info_ptr,
 253     &width, &height, &bit_depth, &color_type,
 254     NULL, NULL, NULL);
 255
 256   /* set-up the transformations */
 257
 258   /* transform paletted images into full-color rgb */
 259   if (color_type == PNG_COLOR_TYPE_PALETTE)
 260     png_set_expand (png_ptr);
 261   /* expand images to bit-depth 8 (only applicable for grayscale images) */
 262   if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
 263     png_set_expand (png_ptr);
 264   /* transform transparency maps into full alpha-channel */
 265   if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
 266     png_set_expand (png_ptr);
 267
 268 #ifdef NJET
 269   /* downgrade 16-bit images to 8-bit */
 270   if (bit_depth == 16)
 271     png_set_strip_16 (png_ptr);
 272   /* transform grayscale images into full-color */
 273   if (color_type == PNG_COLOR_TYPE_GRAY ||
 274     color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
 275     png_set_gray_to_rgb (png_ptr);
 276   /* only if file has a file gamma, we do a correction */
 277   if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
 278     png_set_gamma (png_ptr, (double) 2.2, file_gamma);
 279 #endif
 280
 281   /* all transformations have been registered; now update info_ptr data,
 282    * get rowbytes and channels, and allocate image memory */
 283
 284   png_read_update_info (png_ptr, info_ptr);
 285
 286   /* get the new color-type and bit-depth (after expansion/stripping) */
 287   png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
 288     NULL, NULL, NULL);
 289
 290   /* check for 16-bit files */
 291   if (bit_depth == 16)
 292   {
 293     raw = FALSE;
 294 #ifdef __TURBOC__
 295     pnm_file->flags &= ~((unsigned) _F_BIN);
 296 #endif
 297   }
 298
 299   /* calculate new number of channels and store alpha-presence */
 300   if (color_type == PNG_COLOR_TYPE_GRAY)
 301     channels = 1;
 302   else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
 303     channels = 2;
 304   else if (color_type == PNG_COLOR_TYPE_RGB)
 305     channels = 3;
 306   else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
 307     channels = 4;
 308   else
 309     channels = 0; /* should never happen */
 310   alpha_present = (channels - 1) % 2;
 311
 312   /* check if alpha is expected to be present in file */
 313   if (alpha && !alpha_present)
 314   {
 315     fprintf (stderr, "PNG2PNM\n");
 316     fprintf (stderr, "Error:  PNG-file doesn't contain alpha channel\n");
 317     exit (1);
 318   }
 319
 320   /* row_bytes is the width x number of channels x (bit-depth / 8) */
 321   row_bytes = png_get_rowbytes (png_ptr, info_ptr);
 322
 323   if ((png_pixels = (png_byte *)
 324      malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
 325     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
 326     return FALSE;
 327   }
 328
 329   if ((row_pointers = (png_byte **)
 330      malloc (height * sizeof (png_bytep))) == NULL)
 331   {
 332     png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
 333     free (png_pixels);
 334     png_pixels = NULL;
 335     return FALSE;
 336   }
 337
 338   /* set the individual row_pointers to point at the correct offsets */
 339   for (i = 0; i < ((int) height); i++)
 340     row_pointers[i] = png_pixels + i * row_bytes;
 341
 342   /* now we can go ahead and just read the whole image */
 343   png_read_image (png_ptr, row_pointers);
 344
 345   /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
 346   png_read_end (png_ptr, info_ptr);
 347
 348   /* clean up after the read, and free any memory allocated - REQUIRED */
 349   png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
 350
 351   /* write header of PNM file */
 352
 353   if ((color_type == PNG_COLOR_TYPE_GRAY) ||
 354       (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
 355   {
 356     fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
 357     fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
 358     fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
 359   }
 360   else if ((color_type == PNG_COLOR_TYPE_RGB) ||
 361            (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
 362   {
 363     fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
 364     fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
 365     fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
 366   }
 367
 368   /* write header of PGM file with alpha channel */
 369
 370   if ((alpha) &&
 371       ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
 372        (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
 373   {
 374     fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
 375     fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
 376     fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
 377   }
 378
 379   /* write data to PNM file */
 380   pix_ptr = png_pixels;
 381
 382   for (row = 0; row < (int) height; row++)
 383   {
 384     for (col = 0; col < (int) width; col++)
 385     {
 386       for (i = 0; i < (channels - alpha_present); i++)
 387       {
 388         if (raw)
 389           fputc ((int) *pix_ptr++ , pnm_file);
 390         else
 391           if (bit_depth == 16){
 392             dep_16 = (long) *pix_ptr++;
 393             fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
 394           }
 395           else
 396             fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
 397       }
 398       if (alpha_present)
 399       {
 400         if (!alpha)
 401         {
 402           pix_ptr++; /* alpha */
 403           if (bit_depth == 16)
 404             pix_ptr++;
 405         }
 406         else /* output alpha-channel as pgm file */
 407         {
 408           if (raw)
 409             fputc ((int) *pix_ptr++ , alpha_file);
 410           else
 411             if (bit_depth == 16){
 412               dep_16 = (long) *pix_ptr++;
 413               fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
 414             }
 415             else
 416               fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
 417         }
 418       } /* if alpha_present */
 419
 420       if (!raw)
 421         if (col % 4 == 3)
 422           fprintf (pnm_file, "\n");
 423     } /* end for col */
 424
 425     if (!raw)
 426       if (col % 4 != 0)
 427         fprintf (pnm_file, "\n");
 428   } /* end for row */
 429
 430   if (row_pointers != (unsigned char**) NULL)
 431     free (row_pointers);
 432   if (png_pixels != (unsigned char*) NULL)
 433     free (png_pixels);
 434
 435   return TRUE;
 436
 437 } /* end of source */
 438