2 * pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
3 * copyright (C) 1999 by Willem van Schaik <willem@schaik.com>
5 * version 1.0 - 1999.10.15 - First version.
6 * version 1.1 - 2015.07.29 - Fixed leaks (Glenn Randers-Pehrson)
8 * Permission to use, copy, modify, and distribute this software and
9 * its documentation for any purpose and without fee is hereby granted,
10 * provided that the above copyright notice appear in all copies and
11 * that both that copyright notice and this permission notice appear in
12 * supporting documentation. This software is provided "as is" without
13 * express or implied warranty.
25 #define BOOL unsigned char
31 #define FALSE (BOOL) 0
38 /* to make pnm2png verbose so we can find problems (needs to be before png.h) */
45 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
47 # define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
50 /* function prototypes */
52 int main (int argc, char *argv[]);
54 BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
56 void get_token(FILE *pnm_file, char *token);
57 png_uint_32 get_data (FILE *pnm_file, int depth);
58 png_uint_32 get_value (FILE *pnm_file, int depth);
64 int main(int argc, char *argv[])
69 BOOL interlace = FALSE;
73 for (argi = 1; argi < argc; argi++)
75 if (argv[argi][0] == '-')
77 switch (argv[argi][1])
85 if ((fp_al = fopen (argv[argi], "rb")) == NULL)
87 fprintf (stderr, "PNM2PNG\n");
88 fprintf (stderr, "Error: alpha-channel file %s does not exist\n",
99 fprintf (stderr, "PNM2PNG\n");
100 fprintf (stderr, "Error: unknown option %s\n", argv[argi]);
106 else if (fp_rd == stdin)
108 if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
110 fprintf (stderr, "PNM2PNG\n");
111 fprintf (stderr, "Error: file %s does not exist\n", argv[argi]);
115 else if (fp_wr == stdout)
117 if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
119 fprintf (stderr, "PNM2PNG\n");
120 fprintf (stderr, "Error: can not create PNG-file %s\n", argv[argi]);
126 fprintf (stderr, "PNM2PNG\n");
127 fprintf (stderr, "Error: too many parameters\n");
134 /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
137 setmode (STDIN, O_BINARY);
141 setmode (STDOUT, O_BINARY);
145 /* call the conversion program itself */
146 if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
148 fprintf (stderr, "PNM2PNG\n");
149 fprintf (stderr, "Error: unsuccessful converting to PNG-image\n");
153 /* close input file */
155 /* close output file */
157 /* close alpha file */
170 fprintf (stderr, "PNM2PNG\n");
171 fprintf (stderr, " by Willem van Schaik, 1999\n");
173 fprintf (stderr, " for Turbo-C and Borland-C compilers\n");
175 fprintf (stderr, " for Linux (and Unix) compilers\n");
177 fprintf (stderr, "Usage: pnm2png [options] <file>.<pnm> [<file>.png]\n");
178 fprintf (stderr, " or: ... | pnm2png [options]\n");
179 fprintf (stderr, "Options:\n");
180 fprintf (stderr, " -i[nterlace] write png-file with interlacing on\n");
182 " -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
183 fprintf (stderr, " -h | -? print this help-information\n");
190 BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
193 png_struct *png_ptr = NULL;
194 png_info *info_ptr = NULL;
195 png_byte *png_pixels = NULL;
196 png_byte **row_pointers = NULL;
197 png_byte *pix_ptr = NULL;
198 volatile png_uint_32 row_bytes;
201 char width_token[16];
202 char height_token[16];
203 char maxval_token[16];
204 volatile int color_type=1;
205 unsigned long ul_width=0, ul_alpha_width=0;
206 unsigned long ul_height=0, ul_alpha_height=0;
207 unsigned long ul_maxval=0;
208 volatile png_uint_32 width=0, height=0;
209 volatile png_uint_32 alpha_width=0, alpha_height=0;
211 volatile int bit_depth = 0;
216 BOOL raw, alpha_raw = FALSE;
217 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
218 BOOL packed_bitmap = FALSE;
223 /* read header of PNM file */
225 get_token(pnm_file, type_token);
226 if (type_token[0] != 'P')
230 else if ((type_token[1] == '1') || (type_token[1] == '4'))
232 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
233 raw = (type_token[1] == '4');
234 color_type = PNG_COLOR_TYPE_GRAY;
235 get_token(pnm_file, width_token);
236 sscanf (width_token, "%lu", &ul_width);
237 width = (png_uint_32) ul_width;
238 get_token(pnm_file, height_token);
239 sscanf (height_token, "%lu", &ul_height);
240 height = (png_uint_32) ul_height;
242 packed_bitmap = TRUE;
244 fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");
245 fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
248 else if ((type_token[1] == '2') || (type_token[1] == '5'))
250 raw = (type_token[1] == '5');
251 color_type = PNG_COLOR_TYPE_GRAY;
252 get_token(pnm_file, width_token);
253 sscanf (width_token, "%lu", &ul_width);
254 width = (png_uint_32) ul_width;
255 get_token(pnm_file, height_token);
256 sscanf (height_token, "%lu", &ul_height);
257 height = (png_uint_32) ul_height;
258 get_token(pnm_file, maxval_token);
259 sscanf (maxval_token, "%lu", &ul_maxval);
260 maxval = (png_uint_32) ul_maxval;
264 else if (maxval <= 3)
266 else if (maxval <= 15)
268 else if (maxval <= 255)
270 else /* if (maxval <= 65535) */
273 else if ((type_token[1] == '3') || (type_token[1] == '6'))
275 raw = (type_token[1] == '6');
276 color_type = PNG_COLOR_TYPE_RGB;
277 get_token(pnm_file, width_token);
278 sscanf (width_token, "%lu", &ul_width);
279 width = (png_uint_32) ul_width;
280 get_token(pnm_file, height_token);
281 sscanf (height_token, "%lu", &ul_height);
282 height = (png_uint_32) ul_height;
283 get_token(pnm_file, maxval_token);
284 sscanf (maxval_token, "%lu", &ul_maxval);
285 maxval = (png_uint_32) ul_maxval;
288 else if (maxval <= 3)
290 else if (maxval <= 15)
292 else if (maxval <= 255)
294 else /* if (maxval <= 65535) */
302 /* read header of PGM file with alpha channel */
306 if (color_type == PNG_COLOR_TYPE_GRAY)
307 color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
308 if (color_type == PNG_COLOR_TYPE_RGB)
309 color_type = PNG_COLOR_TYPE_RGB_ALPHA;
311 get_token(alpha_file, type_token);
312 if (type_token[0] != 'P')
316 else if ((type_token[1] == '2') || (type_token[1] == '5'))
318 alpha_raw = (type_token[1] == '5');
319 get_token(alpha_file, width_token);
320 sscanf (width_token, "%lu", &ul_alpha_width);
321 alpha_width=(png_uint_32) ul_alpha_width;
322 if (alpha_width != width)
324 get_token(alpha_file, height_token);
325 sscanf (height_token, "%lu", &ul_alpha_height);
326 alpha_height = (png_uint_32) ul_alpha_height;
327 if (alpha_height != height)
329 get_token(alpha_file, maxval_token);
330 sscanf (maxval_token, "%lu", &ul_maxval);
331 maxval = (png_uint_32) ul_maxval;
334 else if (maxval <= 3)
336 else if (maxval <= 15)
338 else if (maxval <= 255)
340 else /* if (maxval <= 65535) */
342 if (alpha_depth != bit_depth)
351 /* calculate the number of channels and store alpha-presence */
352 if (color_type == PNG_COLOR_TYPE_GRAY)
354 else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
356 else if (color_type == PNG_COLOR_TYPE_RGB)
358 else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
362 channels = 0; /* cannot happen */
365 alpha_present = (channels - 1) % 2;
367 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
369 /* row data is as many bytes as can fit width x channels x bit_depth */
370 row_bytes = (width * channels * bit_depth + 7) / 8;
373 /* row_bytes is the width x number of channels x (bit-depth / 8) */
374 row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
376 if ((png_pixels = (png_byte *)
377 malloc (row_bytes * height * sizeof (png_byte))) == NULL)
380 /* read data from PNM file */
381 pix_ptr = png_pixels;
383 for (row = 0; row < (int) height; row++)
385 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
387 for (i = 0; i < (int) row_bytes; i++)
388 /* png supports this format natively so no conversion is needed */
389 *pix_ptr++ = get_data (pnm_file, 8);
393 for (col = 0; col < (int) width; col++)
395 for (i = 0; i < (channels - alpha_present); i++)
398 *pix_ptr++ = get_data (pnm_file, bit_depth);
401 *pix_ptr++ = get_value (pnm_file, bit_depth);
404 tmp16 = get_value (pnm_file, bit_depth);
405 *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
407 *pix_ptr = (png_byte) (tmp16 & 0xFF);
412 if (alpha) /* read alpha-channel from pgm file */
415 *pix_ptr++ = get_data (alpha_file, alpha_depth);
417 if (alpha_depth <= 8)
418 *pix_ptr++ = get_value (alpha_file, bit_depth);
421 tmp16 = get_value (alpha_file, bit_depth);
422 *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
423 *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
426 } /* if packed_bitmap */
430 /* prepare the standard PNG structures */
431 png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), NULL, NULL,
439 info_ptr = png_create_info_struct (png_ptr);
442 png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
448 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
449 if (packed_bitmap == TRUE)
451 png_set_packing (png_ptr);
452 png_set_invert_mono (png_ptr);
456 /* setjmp() must be called in every function that calls a PNG-reading libpng function */
457 if (setjmp (png_jmpbuf(png_ptr)))
459 png_destroy_write_struct (&png_ptr, &info_ptr);
465 /* initialize the png structure */
466 png_init_io (png_ptr, png_file);
468 /* we're going to write more or less the same PNG as the input file */
469 png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
470 (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
471 PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
473 /* write the file header information */
474 png_write_info (png_ptr, info_ptr);
476 /* if needed we will allocate memory for an new array of row-pointers */
477 if (row_pointers == (unsigned char**) NULL)
479 if ((row_pointers = (png_byte **)
480 malloc (height * sizeof (png_bytep))) == NULL)
482 png_destroy_write_struct (&png_ptr, &info_ptr);
489 /* set the individual row_pointers to point at the correct offsets */
490 for (i = 0; i < (int) height; i++)
491 row_pointers[i] = png_pixels + i * row_bytes;
493 /* write out the entire image data in one call */
494 png_write_image (png_ptr, row_pointers);
496 /* write the additional chunks to the PNG file (not really needed) */
497 png_write_end (png_ptr, info_ptr);
499 /* clean up after the write, and free any memory allocated */
500 png_destroy_write_struct (&png_ptr, &info_ptr);
502 if (row_pointers != (unsigned char**) NULL)
504 if (png_pixels != (unsigned char*) NULL)
508 } /* end of pnm2png */
511 * get_token() - gets the first string after whitespace
514 void get_token(FILE *pnm_file, char *token)
519 /* remove white-space and comment lines */
522 ret = fgetc(pnm_file);
524 /* the rest of this line is a comment */
527 ret = fgetc(pnm_file);
529 while ((ret != '\n') && (ret != '\r') && (ret != EOF));
531 if (ret == EOF) break;
532 token[i] = (unsigned char) ret;
534 while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
539 ret = fgetc(pnm_file);
540 if (ret == EOF) break;
542 token[i] = (unsigned char) ret;
544 while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
552 * get_data() - takes first byte and converts into next pixel value,
553 * taking as much bits as defined by bit-depth and
554 * using the bit-depth to fill up a byte (0Ah -> AAh)
557 png_uint_32 get_data (FILE *pnm_file, int depth)
559 static int bits_left = 0;
560 static int old_value = 0;
563 png_uint_32 ret_value;
566 for (i = 0; i < depth; i++)
567 mask = (mask >> 1) | 0x80;
571 old_value = fgetc (pnm_file);
575 ret_value = old_value & mask;
576 for (i = 1; i < (8 / depth); i++)
577 ret_value = ret_value || (ret_value >> depth);
579 old_value = (old_value << depth) & 0xFF;
586 * get_value() - takes first (numeric) string and converts into number,
587 * using the bit-depth to fill up a byte (0Ah -> AAh)
590 png_uint_32 get_value (FILE *pnm_file, int depth)
592 static png_uint_32 mask = 0;
594 unsigned long ul_ret_value;
595 png_uint_32 ret_value;
599 for (i = 0; i < depth; i++)
600 mask = (mask << 1) | 0x01;
602 get_token (pnm_file, (char *) token);
603 sscanf ((const char *) token, "%lu", &ul_ret_value);
604 ret_value = (png_uint_32) ul_ret_value;
609 for (i = 0; i < (8 / depth); i++)
610 ret_value = (ret_value << depth) || ret_value;