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comparison ext/libpng-1.2.29/contrib/pngminus/png2pnm.c @ 0:4a0efb7baf70

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* Datasets becomes the new trunk and retires after that :-)
author mvbarracuda@33b003aa-7bff-0310-803a-e67f0ece8222
date Sun, 29 Jun 2008 18:44:17 +0000
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-1:000000000000 0:4a0efb7baf70
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
22 #ifndef BOOL
23 #define BOOL unsigned char
24 #endif
25 #ifndef TRUE
26 #define TRUE (BOOL) 1
27 #endif
28 #ifndef FALSE
29 #define FALSE (BOOL) 0
30 #endif
31
32 #ifdef __TURBOC__
33 #define STDIN 0
34 #define STDOUT 1
35 #define STDERR 2
36 #endif
37
38 /* to make png2pnm verbose so we can find problems (needs to be before png.h) */
39 #ifndef PNG_DEBUG
40 #define PNG_DEBUG 0
41 #endif
42
43 #include "png.h"
44
45 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
46 #ifndef png_jmpbuf
47 # define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
48 #endif
49
50 /* function prototypes */
51
52 int main (int argc, char *argv[]);
53 void usage ();
54 BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha);
55
56 /*
57 * main
58 */
59
60 int main(int argc, char *argv[])
61 {
62 FILE *fp_rd = stdin;
63 FILE *fp_wr = stdout;
64 FILE *fp_al = NULL;
65 BOOL raw = TRUE;
66 BOOL alpha = FALSE;
67 int argi;
68
69 for (argi = 1; argi < argc; argi++)
70 {
71 if (argv[argi][0] == '-')
72 {
73 switch (argv[argi][1])
74 {
75 case 'n':
76 raw = FALSE;
77 break;
78 case 'r':
79 raw = TRUE;
80 break;
81 case 'a':
82 alpha = TRUE;
83 argi++;
84 if ((fp_al = fopen (argv[argi], "wb")) == NULL)
85 {
86 fprintf (stderr, "PNM2PNG\n");
87 fprintf (stderr, "Error: can not create alpha-channel file %s\n", argv[argi]);
88 exit (1);
89 }
90 break;
91 case 'h':
92 case '?':
93 usage();
94 exit(0);
95 break;
96 default:
97 fprintf (stderr, "PNG2PNM\n");
98 fprintf (stderr, "Error: unknown option %s\n", argv[argi]);
99 usage();
100 exit(1);
101 break;
102 } /* end switch */
103 }
104 else if (fp_rd == stdin)
105 {
106 if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
107 {
108 fprintf (stderr, "PNG2PNM\n");
109 fprintf (stderr, "Error: file %s does not exist\n", argv[argi]);
110 exit (1);
111 }
112 }
113 else if (fp_wr == stdout)
114 {
115 if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
116 {
117 fprintf (stderr, "PNG2PNM\n");
118 fprintf (stderr, "Error: can not create file %s\n", argv[argi]);
119 exit (1);
120 }
121 }
122 else
123 {
124 fprintf (stderr, "PNG2PNM\n");
125 fprintf (stderr, "Error: too many parameters\n");
126 usage();
127 exit(1);
128 }
129 } /* end for */
130
131 #ifdef __TURBOC__
132 /* set stdin/stdout if required to binary */
133 if (fp_rd == stdin)
134 {
135 setmode (STDIN, O_BINARY);
136 }
137 if ((raw) && (fp_wr == stdout))
138 {
139 setmode (STDOUT, O_BINARY);
140 }
141 #endif
142
143 /* call the conversion program itself */
144 if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE)
145 {
146 fprintf (stderr, "PNG2PNM\n");
147 fprintf (stderr, "Error: unsuccessful convertion of PNG-image\n");
148 exit(1);
149 }
150
151 /* close input file */
152 fclose (fp_rd);
153 /* close output file */
154 fclose (fp_wr);
155 /* close alpha file */
156 if (alpha)
157 fclose (fp_al);
158
159 return 0;
160 }
161
162 /*
163 * usage
164 */
165
166 void usage()
167 {
168 fprintf (stderr, "PNG2PNM\n");
169 fprintf (stderr, " by Willem van Schaik, 1999\n");
170 #ifdef __TURBOC__
171 fprintf (stderr, " for Turbo-C and Borland-C compilers\n");
172 #else
173 fprintf (stderr, " for Linux (and Unix) compilers\n");
174 #endif
175 fprintf (stderr, "Usage: png2pnm [options] <file>.png [<file>.pnm]\n");
176 fprintf (stderr, " or: ... | png2pnm [options]\n");
177 fprintf (stderr, "Options:\n");
178 fprintf (stderr, " -r[aw] write pnm-file in binary format (P4/P5/P6) (default)\n");
179 fprintf (stderr, " -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n");
180 fprintf (stderr, " -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n");
181 fprintf (stderr, " -h | -? print this help-information\n");
182 }
183
184 /*
185 * png2pnm
186 */
187
188 BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha)
189 {
190 png_struct *png_ptr = NULL;
191 png_info *info_ptr = NULL;
192 png_byte buf[8];
193 png_byte *png_pixels = NULL;
194 png_byte **row_pointers = NULL;
195 png_byte *pix_ptr = NULL;
196 png_uint_32 row_bytes;
197
198 png_uint_32 width;
199 png_uint_32 height;
200 int bit_depth;
201 int channels;
202 int color_type;
203 int alpha_present;
204 int row, col;
205 int ret;
206 int i;
207 long dep_16;
208
209 /* read and check signature in PNG file */
210 ret = fread (buf, 1, 8, png_file);
211 if (ret != 8)
212 return FALSE;
213
214 ret = png_check_sig (buf, 8);
215 if (!ret)
216 return FALSE;
217
218 /* create png and info structures */
219
220 png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING,
221 NULL, NULL, NULL);
222 if (!png_ptr)
223 return FALSE; /* out of memory */
224
225 info_ptr = png_create_info_struct (png_ptr);
226 if (!info_ptr)
227 {
228 png_destroy_read_struct (&png_ptr, NULL, NULL);
229 return FALSE; /* out of memory */
230 }
231
232 if (setjmp (png_jmpbuf(png_ptr)))
233 {
234 png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
235 return FALSE;
236 }
237
238 /* set up the input control for C streams */
239 png_init_io (png_ptr, png_file);
240 png_set_sig_bytes (png_ptr, 8); /* we already read the 8 signature bytes */
241
242 /* read the file information */
243 png_read_info (png_ptr, info_ptr);
244
245 /* get size and bit-depth of the PNG-image */
246 png_get_IHDR (png_ptr, info_ptr,
247 &width, &height, &bit_depth, &color_type,
248 NULL, NULL, NULL);
249
250 /* set-up the transformations */
251
252 /* transform paletted images into full-color rgb */
253 if (color_type == PNG_COLOR_TYPE_PALETTE)
254 png_set_expand (png_ptr);
255 /* expand images to bit-depth 8 (only applicable for grayscale images) */
256 if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
257 png_set_expand (png_ptr);
258 /* transform transparency maps into full alpha-channel */
259 if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS))
260 png_set_expand (png_ptr);
261
262 #ifdef NJET
263 /* downgrade 16-bit images to 8 bit */
264 if (bit_depth == 16)
265 png_set_strip_16 (png_ptr);
266 /* transform grayscale images into full-color */
267 if (color_type == PNG_COLOR_TYPE_GRAY ||
268 color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
269 png_set_gray_to_rgb (png_ptr);
270 /* only if file has a file gamma, we do a correction */
271 if (png_get_gAMA (png_ptr, info_ptr, &file_gamma))
272 png_set_gamma (png_ptr, (double) 2.2, file_gamma);
273 #endif
274
275 /* all transformations have been registered; now update info_ptr data,
276 * get rowbytes and channels, and allocate image memory */
277
278 png_read_update_info (png_ptr, info_ptr);
279
280 /* get the new color-type and bit-depth (after expansion/stripping) */
281 png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
282 NULL, NULL, NULL);
283
284 /* check for 16-bit files */
285 if (bit_depth == 16)
286 {
287 raw = FALSE;
288 #ifdef __TURBOC__
289 pnm_file->flags &= ~((unsigned) _F_BIN);
290 #endif
291 }
292
293 /* calculate new number of channels and store alpha-presence */
294 if (color_type == PNG_COLOR_TYPE_GRAY)
295 channels = 1;
296 else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
297 channels = 2;
298 else if (color_type == PNG_COLOR_TYPE_RGB)
299 channels = 3;
300 else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
301 channels = 4;
302 else
303 channels = 0; /* should never happen */
304 alpha_present = (channels - 1) % 2;
305
306 /* check if alpha is expected to be present in file */
307 if (alpha && !alpha_present)
308 {
309 fprintf (stderr, "PNG2PNM\n");
310 fprintf (stderr, "Error: PNG-file doesn't contain alpha channel\n");
311 exit (1);
312 }
313
314 /* row_bytes is the width x number of channels x (bit-depth / 8) */
315 row_bytes = png_get_rowbytes (png_ptr, info_ptr);
316
317 if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) {
318 png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
319 return FALSE;
320 }
321
322 if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
323 {
324 png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
325 free (png_pixels);
326 png_pixels = NULL;
327 return FALSE;
328 }
329
330 /* set the individual row_pointers to point at the correct offsets */
331 for (i = 0; i < (height); i++)
332 row_pointers[i] = png_pixels + i * row_bytes;
333
334 /* now we can go ahead and just read the whole image */
335 png_read_image (png_ptr, row_pointers);
336
337 /* read rest of file, and get additional chunks in info_ptr - REQUIRED */
338 png_read_end (png_ptr, info_ptr);
339
340 /* clean up after the read, and free any memory allocated - REQUIRED */
341 png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL);
342
343 /* write header of PNM file */
344
345 if ((color_type == PNG_COLOR_TYPE_GRAY) ||
346 (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
347 {
348 fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2");
349 fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
350 fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
351 }
352 else if ((color_type == PNG_COLOR_TYPE_RGB) ||
353 (color_type == PNG_COLOR_TYPE_RGB_ALPHA))
354 {
355 fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3");
356 fprintf (pnm_file, "%d %d\n", (int) width, (int) height);
357 fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
358 }
359
360 /* write header of PGM file with alpha channel */
361
362 if ((alpha) &&
363 ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||
364 (color_type == PNG_COLOR_TYPE_RGB_ALPHA)))
365 {
366 fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2");
367 fprintf (alpha_file, "%d %d\n", (int) width, (int) height);
368 fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L));
369 }
370
371 /* write data to PNM file */
372 pix_ptr = png_pixels;
373
374 for (row = 0; row < height; row++)
375 {
376 for (col = 0; col < width; col++)
377 {
378 for (i = 0; i < (channels - alpha_present); i++)
379 {
380 if (raw)
381 fputc ((int) *pix_ptr++ , pnm_file);
382 else
383 if (bit_depth == 16){
384 dep_16 = (long) *pix_ptr++;
385 fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++));
386 }
387 else
388 fprintf (pnm_file, "%ld ", (long) *pix_ptr++);
389 }
390 if (alpha_present)
391 {
392 if (!alpha)
393 {
394 pix_ptr++; /* alpha */
395 if (bit_depth == 16)
396 pix_ptr++;
397 }
398 else /* output alpha-channel as pgm file */
399 {
400 if (raw)
401 fputc ((int) *pix_ptr++ , alpha_file);
402 else
403 if (bit_depth == 16){
404 dep_16 = (long) *pix_ptr++;
405 fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++);
406 }
407 else
408 fprintf (alpha_file, "%ld ", (long) *pix_ptr++);
409 }
410 } /* if alpha_present */
411
412 if (!raw)
413 if (col % 4 == 3)
414 fprintf (pnm_file, "\n");
415 } /* end for col */
416
417 if (!raw)
418 if (col % 4 != 0)
419 fprintf (pnm_file, "\n");
420 } /* end for row */
421
422 if (row_pointers != (unsigned char**) NULL)
423 free (row_pointers);
424 if (png_pixels != (unsigned char*) NULL)
425 free (png_pixels);
426
427 return TRUE;
428
429 } /* end of source */
430