1 /*
2 * pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
3 * copyright (C) 1999-2019 by Willem van Schaik <willem at schaik dot com>
4 *
5 * This software is released under the MIT license. For conditions of
6 * distribution and use, see the LICENSE file part of this package.
7 */
8
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <fcntl.h>
12
13 #ifndef BOOL
14 #define BOOL unsigned char
15 #endif
16 #ifndef TRUE
17 #define TRUE (BOOL) 1
18 #endif
19 #ifndef FALSE
20 #define FALSE (BOOL) 0
21 #endif
22
23 /* make pnm2png verbose so we can find problems (needs to be before png.h) */
24 #ifndef PNG_DEBUG
25 #define PNG_DEBUG 0
26 #endif
27
28 #include "png.h"
29
30 /* function prototypes */
31
32 int main (int argc, char *argv[]);
33 void usage ();
34 BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file,
35 BOOL interlace, BOOL alpha);
36 void get_token (FILE *pnm_file, char *token_buf, size_t token_buf_size);
37 png_uint_32 get_data (FILE *pnm_file, int depth);
38 png_uint_32 get_value (FILE *pnm_file, int depth);
39
40 /*
41 * main
42 */
43
44 int main (int argc, char *argv[])
45 {
46 FILE *fp_rd = stdin;
47 FILE *fp_al = NULL;
48 FILE *fp_wr = stdout;
49 BOOL interlace = FALSE;
50 BOOL alpha = FALSE;
51 int argi;
52
53 for (argi = 1; argi < argc; argi++)
54 {
55 if (argv[argi][0] == '-')
56 {
57 switch (argv[argi][1])
58 {
59 case 'i':
60 interlace = TRUE;
61 break;
62 case 'a':
63 alpha = TRUE;
64 argi++;
65 if ((fp_al = fopen (argv[argi], "rb")) == NULL)
66 {
67 fprintf (stderr, "PNM2PNG\n");
68 fprintf (stderr, "Error: alpha-channel file %s does not exist\n",
69 argv[argi]);
70 exit (1);
71 }
72 break;
73 case 'h':
74 case '?':
75 usage ();
76 exit (0);
77 break;
78 default:
79 fprintf (stderr, "PNM2PNG\n");
80 fprintf (stderr, "Error: unknown option %s\n", argv[argi]);
81 usage ();
82 exit (1);
83 break;
84 } /* end switch */
85 }
86 else if (fp_rd == stdin)
87 {
88 if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
89 {
90 fprintf (stderr, "PNM2PNG\n");
91 fprintf (stderr, "Error: file %s does not exist\n", argv[argi]);
92 exit (1);
93 }
94 }
95 else if (fp_wr == stdout)
96 {
97 if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
98 {
99 fprintf (stderr, "PNM2PNG\n");
100 fprintf (stderr, "Error: cannot create PNG-file %s\n", argv[argi]);
101 exit (1);
102 }
103 }
104 else
105 {
106 fprintf (stderr, "PNM2PNG\n");
107 fprintf (stderr, "Error: too many parameters\n");
108 usage ();
109 exit (1);
110 }
111 } /* end for */
112
113 #if defined(O_BINARY) && (O_BINARY != 0)
114 /* set stdin/stdout to binary,
115 * we're reading the PNM always! in binary format
116 */
117 if (fp_rd == stdin)
118 setmode (fileno (stdin), O_BINARY);
119 if (fp_wr == stdout)
120 setmode (fileno (stdout), O_BINARY);
121 #endif
122
123 /* call the conversion program itself */
124 if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
125 {
126 fprintf (stderr, "PNM2PNG\n");
127 fprintf (stderr, "Error: unsuccessful converting to PNG-image\n");
128 exit (1);
129 }
130
131 /* close input file */
132 fclose (fp_rd);
133 /* close output file */
134 fclose (fp_wr);
135 /* close alpha file */
136 if (alpha)
137 fclose (fp_al);
138
139 return 0;
140 }
141
142 /*
143 * usage
144 */
145
146 void usage ()
147 {
148 fprintf (stderr, "PNM2PNG\n");
149 fprintf (stderr, " by Willem van Schaik, 1999\n");
150 fprintf (stderr, "Usage: pnm2png [options] <file>.<pnm> [<file>.png]\n");
151 fprintf (stderr, " or: ... | pnm2png [options]\n");
152 fprintf (stderr, "Options:\n");
153 fprintf (stderr, " -i[nterlace] write png-file with interlacing on\n");
154 fprintf (stderr,
155 " -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
156 fprintf (stderr, " -h | -? print this help-information\n");
157 }
158
159 /*
160 * pnm2png
161 */
162
163 BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file,
164 BOOL interlace, BOOL alpha)
165 {
166 png_struct *png_ptr = NULL;
167 png_info *info_ptr = NULL;
168 png_byte *png_pixels = NULL;
169 png_byte **row_pointers = NULL;
170 png_byte *pix_ptr = NULL;
171 volatile png_uint_32 row_bytes;
172
173 char type_token[16];
174 char width_token[16];
175 char height_token[16];
176 char maxval_token[16];
177 volatile int color_type = 1;
178 unsigned long ul_width = 0, ul_alpha_width = 0;
179 unsigned long ul_height = 0, ul_alpha_height = 0;
180 unsigned long ul_maxval = 0;
181 volatile png_uint_32 width = 0, height = 0;
182 volatile png_uint_32 alpha_width = 0, alpha_height = 0;
183 png_uint_32 maxval;
184 volatile int bit_depth = 0;
185 int channels = 0;
186 int alpha_depth = 0;
187 int alpha_present = 0;
188 int row, col;
189 BOOL raw, alpha_raw = FALSE;
190 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
191 BOOL packed_bitmap = FALSE;
192 #endif
193 png_uint_32 tmp16;
194 int i;
195
196 /* read header of PNM file */
197
198 get_token (pnm_file, type_token, sizeof (type_token));
199 if (type_token[0] != 'P')
200 {
201 return FALSE;
202 }
203 else if ((type_token[1] == '1') || (type_token[1] == '4'))
204 {
205 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
206 raw = (type_token[1] == '4');
207 color_type = PNG_COLOR_TYPE_GRAY;
208 get_token (pnm_file, width_token, sizeof (width_token));
209 sscanf (width_token, "%lu", &ul_width);
210 width = (png_uint_32) ul_width;
211 get_token (pnm_file, height_token, sizeof (height_token));
212 sscanf (height_token, "%lu", &ul_height);
213 height = (png_uint_32) ul_height;
214 bit_depth = 1;
215 packed_bitmap = TRUE;
216 #else
217 fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and\n");
218 fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
219 return FALSE;
220 #endif
221 }
222 else if ((type_token[1] == '2') || (type_token[1] == '5'))
223 {
224 raw = (type_token[1] == '5');
225 color_type = PNG_COLOR_TYPE_GRAY;
226 get_token (pnm_file, width_token, sizeof (width_token));
227 sscanf (width_token, "%lu", &ul_width);
228 width = (png_uint_32) ul_width;
229 get_token (pnm_file, height_token, sizeof (height_token));
230 sscanf (height_token, "%lu", &ul_height);
231 height = (png_uint_32) ul_height;
232 get_token (pnm_file, maxval_token, sizeof (maxval_token));
233 sscanf (maxval_token, "%lu", &ul_maxval);
234 maxval = (png_uint_32) ul_maxval;
235
236 if (maxval <= 1)
237 bit_depth = 1;
238 else if (maxval <= 3)
239 bit_depth = 2;
240 else if (maxval <= 15)
241 bit_depth = 4;
242 else if (maxval <= 255)
243 bit_depth = 8;
244 else if (maxval <= 65535U)
245 bit_depth = 16;
246 else /* maxval > 65535U */
247 return FALSE;
248 }
249 else if ((type_token[1] == '3') || (type_token[1] == '6'))
250 {
251 raw = (type_token[1] == '6');
252 color_type = PNG_COLOR_TYPE_RGB;
253 get_token (pnm_file, width_token, sizeof (width_token));
254 sscanf (width_token, "%lu", &ul_width);
255 width = (png_uint_32) ul_width;
256 get_token (pnm_file, height_token, sizeof (height_token));
257 sscanf (height_token, "%lu", &ul_height);
258 height = (png_uint_32) ul_height;
259 get_token (pnm_file, maxval_token, sizeof (maxval_token));
260 sscanf (maxval_token, "%lu", &ul_maxval);
261 maxval = (png_uint_32) ul_maxval;
262 if (maxval <= 1)
263 bit_depth = 1;
264 else if (maxval <= 3)
265 bit_depth = 2;
266 else if (maxval <= 15)
267 bit_depth = 4;
268 else if (maxval <= 255)
269 bit_depth = 8;
270 else if (maxval <= 65535U)
271 bit_depth = 16;
272 else /* maxval > 65535U */
273 return FALSE;
274 }
275 else
276 {
277 return FALSE;
278 }
279
280 /* read header of PGM file with alpha channel */
281
282 if (alpha)
283 {
284 if (color_type == PNG_COLOR_TYPE_GRAY)
285 color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
286 if (color_type == PNG_COLOR_TYPE_RGB)
287 color_type = PNG_COLOR_TYPE_RGB_ALPHA;
288
289 get_token (alpha_file, type_token, sizeof (type_token));
290 if (type_token[0] != 'P')
291 {
292 return FALSE;
293 }
294 else if ((type_token[1] == '2') || (type_token[1] == '5'))
295 {
296 alpha_raw = (type_token[1] == '5');
297 get_token (alpha_file, width_token, sizeof (width_token));
298 sscanf (width_token, "%lu", &ul_alpha_width);
299 alpha_width = (png_uint_32) ul_alpha_width;
300 if (alpha_width != width)
301 return FALSE;
302 get_token (alpha_file, height_token, sizeof (height_token));
303 sscanf (height_token, "%lu", &ul_alpha_height);
304 alpha_height = (png_uint_32) ul_alpha_height;
305 if (alpha_height != height)
306 return FALSE;
307 get_token (alpha_file, maxval_token, sizeof (maxval_token));
308 sscanf (maxval_token, "%lu", &ul_maxval);
309 maxval = (png_uint_32) ul_maxval;
310 if (maxval <= 1)
311 alpha_depth = 1;
312 else if (maxval <= 3)
313 alpha_depth = 2;
314 else if (maxval <= 15)
315 alpha_depth = 4;
316 else if (maxval <= 255)
317 alpha_depth = 8;
318 else if (maxval <= 65535U)
319 alpha_depth = 16;
320 else /* maxval > 65535U */
321 return FALSE;
322 if (alpha_depth != bit_depth)
323 return FALSE;
324 }
325 else
326 {
327 return FALSE;
328 }
329 } /* end if alpha */
330
331 /* calculate the number of channels and store alpha-presence */
332 if (color_type == PNG_COLOR_TYPE_GRAY)
333 channels = 1;
334 else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
335 channels = 2;
336 else if (color_type == PNG_COLOR_TYPE_RGB)
337 channels = 3;
338 else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
339 channels = 4;
340 #if 0
341 else
342 channels = 0; /* cannot happen */
343 #endif
344
345 alpha_present = (channels - 1) % 2;
346
347 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
348 if (packed_bitmap)
349 {
350 /* row data is as many bytes as can fit width x channels x bit_depth */
351 row_bytes = (width * channels * bit_depth + 7) / 8;
352 }
353 else
354 #endif
355 {
356 /* row_bytes is the width x number of channels x (bit-depth / 8) */
357 row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
358 }
359
360 if ((row_bytes == 0) ||
361 ((size_t) height > (size_t) (-1) / (size_t) row_bytes))
362 {
363 /* too big */
364 return FALSE;
365 }
366 if ((png_pixels = (png_byte *)
367 malloc ((size_t) row_bytes * (size_t) height)) == NULL)
368 {
369 /* out of memory */
370 return FALSE;
371 }
372
373 /* read data from PNM file */
374 pix_ptr = png_pixels;
375
376 for (row = 0; row < (int) height; row++)
377 {
378 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
379 if (packed_bitmap)
380 {
381 for (i = 0; i < (int) row_bytes; i++)
382 {
383 /* png supports this format natively so no conversion is needed */
384 *pix_ptr++ = get_data (pnm_file, 8);
385 }
386 }
387 else
388 #endif
389 {
390 for (col = 0; col < (int) width; col++)
391 {
392 for (i = 0; i < (channels - alpha_present); i++)
393 {
394 if (raw)
395 {
396 *pix_ptr++ = get_data (pnm_file, bit_depth);
397 }
398 else
399 {
400 if (bit_depth <= 8)
401 {
402 *pix_ptr++ = get_value (pnm_file, bit_depth);
403 }
404 else
405 {
406 tmp16 = get_value (pnm_file, bit_depth);
407 *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
408 pix_ptr++;
409 *pix_ptr = (png_byte) (tmp16 & 0xFF);
410 pix_ptr++;
411 }
412 }
413 }
414
415 if (alpha) /* read alpha-channel from pgm file */
416 {
417 if (alpha_raw)
418 {
419 *pix_ptr++ = get_data (alpha_file, alpha_depth);
420 }
421 else
422 {
423 if (alpha_depth <= 8)
424 {
425 *pix_ptr++ = get_value (alpha_file, bit_depth);
426 }
427 else
428 {
429 tmp16 = get_value (alpha_file, bit_depth);
430 *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
431 *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
432 }
433 }
434 } /* end if alpha */
435 } /* end if packed_bitmap */
436 } /* end for col */
437 } /* end for row */
438
439 /* prepare the standard PNG structures */
440 png_ptr = png_create_write_struct (png_get_libpng_ver(NULL),
441 NULL, NULL, NULL);
442 if (!png_ptr)
443 {
444 free (png_pixels);
445 return FALSE;
446 }
447 info_ptr = png_create_info_struct (png_ptr);
448 if (!info_ptr)
449 {
450 png_destroy_write_struct (&png_ptr, NULL);
451 free (png_pixels);
452 return FALSE;
453 }
454
455 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
456 if (packed_bitmap == TRUE)
457 {
458 png_set_packing (png_ptr);
459 png_set_invert_mono (png_ptr);
460 }
461 #endif
462
463 if (setjmp (png_jmpbuf (png_ptr)))
464 {
465 png_destroy_write_struct (&png_ptr, &info_ptr);
466 free (png_pixels);
467 return FALSE;
468 }
469
470 /* initialize the png structure */
471 png_init_io (png_ptr, png_file);
472
473 /* we're going to write more or less the same PNG as the input file */
474 png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
475 (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
476 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
477
478 /* write the file header information */
479 png_write_info (png_ptr, info_ptr);
480
481 /* if needed we will allocate memory for an new array of row-pointers */
482 if (row_pointers == NULL)
483 {
484 if ((row_pointers = (png_byte **)
485 malloc (height * sizeof (png_byte *))) == NULL)
486 {
487 png_destroy_write_struct (&png_ptr, &info_ptr);
488 free (png_pixels);
489 return FALSE;
490 }
491 }
492
493 /* set the individual row_pointers to point at the correct offsets */
494 for (i = 0; i < (int) height; i++)
495 row_pointers[i] = png_pixels + i * row_bytes;
496
497 /* write out the entire image data in one call */
498 png_write_image (png_ptr, row_pointers);
499
500 /* write the additional chunks to the PNG file (not really needed) */
501 png_write_end (png_ptr, info_ptr);
502
503 /* clean up after the write, and free any memory allocated */
504 png_destroy_write_struct (&png_ptr, &info_ptr);
505
506 if (row_pointers != NULL)
507 free (row_pointers);
508 if (png_pixels != NULL)
509 free (png_pixels);
510
511 return TRUE;
512 } /* end of pnm2png */
513
514 /*
515 * get_token - gets the first string after whitespace
516 */
517
518 void get_token (FILE *pnm_file, char *token_buf, size_t token_buf_size)
519 {
520 size_t i = 0;
521 int ret;
522
523 /* remove white-space and comment lines */
524 do
525 {
526 ret = fgetc (pnm_file);
527 if (ret == '#')
528 {
529 /* the rest of this line is a comment */
530 do
531 {
532 ret = fgetc (pnm_file);
533 }
534 while ((ret != '\n') && (ret != '\r') && (ret != EOF));
535 }
536 if (ret == EOF) break;
537 token_buf[i] = (char) ret;
538 }
539 while ((ret == '\n') || (ret == '\r') || (ret == ' '));
540
541 /* read string */
542 do
543 {
544 ret = fgetc (pnm_file);
545 if (ret == EOF) break;
546 if (++i == token_buf_size - 1) break;
547 token_buf[i] = (char) ret;
548 }
549 while ((ret != '\n') && (ret != '\r') && (ret != ' '));
550
551 token_buf[i] = '\0';
552
553 return;
554 }
555
556 /*
557 * get_data - takes first byte and converts into next pixel value,
558 * taking as much bits as defined by bit-depth and
559 * using the bit-depth to fill up a byte (0Ah -> AAh)
560 */
561
562 png_uint_32 get_data (FILE *pnm_file, int depth)
563 {
564 static int bits_left = 0;
565 static int old_value = 0;
566 static int mask = 0;
567 int i;
568 png_uint_32 ret_value;
569
570 if (mask == 0)
571 for (i = 0; i < depth; i++)
572 mask = (mask >> 1) | 0x80;
573
574 if (bits_left <= 0)
575 {
576 old_value = fgetc (pnm_file);
577 bits_left = 8;
578 }
579
580 ret_value = old_value & mask;
581 for (i = 1; i < (8 / depth); i++)
582 ret_value = ret_value || (ret_value >> depth);
583
584 old_value = (old_value << depth) & 0xFF;
585 bits_left -= depth;
586
587 return ret_value;
588 }
589
590 /*
591 * get_value - takes first (numeric) string and converts into number,
592 * using the bit-depth to fill up a byte (0Ah -> AAh)
593 */
594
595 png_uint_32 get_value (FILE *pnm_file, int depth)
596 {
597 static png_uint_32 mask = 0;
598 char token[16];
599 unsigned long ul_ret_value;
600 png_uint_32 ret_value;
601 int i = 0;
602
603 if (mask == 0)
604 for (i = 0; i < depth; i++)
605 mask = (mask << 1) | 0x01;
606
607 get_token (pnm_file, token, sizeof (token));
608 sscanf (token, "%lu", &ul_ret_value);
609 ret_value = (png_uint_32) ul_ret_value;
610
611 ret_value &= mask;
612
613 if (depth < 8)
614 for (i = 0; i < (8 / depth); i++)
615 ret_value = (ret_value << depth) || ret_value;
616
617 return ret_value;
618 }
619
620 /* end of source */