src/third-party/libpng/contrib/pngminus/png2pnm.c (view raw)
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
53int main (int argc, char *argv[]);
54void usage ();
55BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw,
56 BOOL alpha);
57
58/*
59 * main
60 */
61
62int 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
169void 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
193BOOL 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