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.
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.
23
#define BOOL unsigned char
29
#define FALSE (BOOL) 0
36
/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
43
/* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
45
# define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
48
/* function prototypes */
50
int main (int argc, char *argv[]);
52
BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
53
void get_token(FILE *pnm_file, char *token);
54
png_uint_32 get_data (FILE *pnm_file, int depth);
55
png_uint_32 get_value (FILE *pnm_file, int depth);
61
int main(int argc, char *argv[])
66
BOOL interlace = FALSE;
70
for (argi = 1; argi < argc; argi++)
72
if (argv[argi][0] == '-')
74
switch (argv[argi][1])
82
if ((fp_al = fopen (argv[argi], "rb")) == NULL)
84
fprintf (stderr, "PNM2PNG\n");
85
fprintf (stderr, "Error: alpha-channel file %s does not exist\n",
96
fprintf (stderr, "PNM2PNG\n");
97
fprintf (stderr, "Error: unknown option %s\n", argv[argi]);
103
else if (fp_rd == stdin)
105
if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
107
fprintf (stderr, "PNM2PNG\n");
108
fprintf (stderr, "Error: file %s does not exist\n", argv[argi]);
112
else if (fp_wr == stdout)
114
if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
116
fprintf (stderr, "PNM2PNG\n");
117
fprintf (stderr, "Error: can not create PNG-file %s\n", argv[argi]);
123
fprintf (stderr, "PNM2PNG\n");
124
fprintf (stderr, "Error: too many parameters\n");
131
/* set stdin/stdout to binary, we're reading the PNM always! in binary format */
134
setmode (STDIN, O_BINARY);
138
setmode (STDOUT, O_BINARY);
142
/* call the conversion program itself */
143
if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
145
fprintf (stderr, "PNM2PNG\n");
146
fprintf (stderr, "Error: unsuccessful converting to PNG-image\n");
150
/* close input file */
152
/* close output file */
154
/* close alpha file */
167
fprintf (stderr, "PNM2PNG\n");
168
fprintf (stderr, " by Willem van Schaik, 1999\n");
170
fprintf (stderr, " for Turbo-C and Borland-C compilers\n");
172
fprintf (stderr, " for Linux (and Unix) compilers\n");
174
fprintf (stderr, "Usage: pnm2png [options] <file>.<pnm> [<file>.png]\n");
175
fprintf (stderr, " or: ... | pnm2png [options]\n");
176
fprintf (stderr, "Options:\n");
177
fprintf (stderr, " -i[nterlace] write png-file with interlacing on\n");
178
fprintf (stderr, " -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
179
fprintf (stderr, " -h | -? print this help-information\n");
186
BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
188
png_struct *png_ptr = NULL;
189
png_info *info_ptr = NULL;
190
png_byte *png_pixels = NULL;
191
png_byte **row_pointers = NULL;
192
png_byte *pix_ptr = NULL;
193
png_uint_32 row_bytes;
196
char width_token[16];
197
char height_token[16];
198
char maxval_token[16];
200
png_uint_32 width, alpha_width;
201
png_uint_32 height, alpha_height;
208
BOOL raw, alpha_raw = FALSE;
212
/* read header of PNM file */
214
get_token(pnm_file, type_token);
215
if (type_token[0] != 'P')
219
else if ((type_token[1] == '1') || (type_token[1] == '4'))
221
raw = (type_token[1] == '4');
222
color_type = PNG_COLOR_TYPE_GRAY;
225
else if ((type_token[1] == '2') || (type_token[1] == '5'))
227
raw = (type_token[1] == '5');
228
color_type = PNG_COLOR_TYPE_GRAY;
229
get_token(pnm_file, width_token);
230
sscanf (width_token, "%lu", &width);
231
get_token(pnm_file, height_token);
232
sscanf (height_token, "%lu", &height);
233
get_token(pnm_file, maxval_token);
234
sscanf (maxval_token, "%lu", &maxval);
237
else if (maxval <= 3)
239
else if (maxval <= 15)
241
else if (maxval <= 255)
243
else /* if (maxval <= 65535) */
246
else if ((type_token[1] == '3') || (type_token[1] == '6'))
248
raw = (type_token[1] == '6');
249
color_type = PNG_COLOR_TYPE_RGB;
250
get_token(pnm_file, width_token);
251
sscanf (width_token, "%lu", &width);
252
get_token(pnm_file, height_token);
253
sscanf (height_token, "%lu", &height);
254
get_token(pnm_file, maxval_token);
255
sscanf (maxval_token, "%lu", &maxval);
258
else if (maxval <= 3)
260
else if (maxval <= 15)
262
else if (maxval <= 255)
264
else /* if (maxval <= 65535) */
272
/* read header of PGM file with alpha channel */
276
if (color_type == PNG_COLOR_TYPE_GRAY)
277
color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
278
if (color_type == PNG_COLOR_TYPE_RGB)
279
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
281
get_token(alpha_file, type_token);
282
if (type_token[0] != 'P')
286
else if ((type_token[1] == '2') || (type_token[1] == '5'))
288
alpha_raw = (type_token[1] == '5');
289
get_token(alpha_file, width_token);
290
sscanf (width_token, "%lu", &alpha_width);
291
if (alpha_width != width)
293
get_token(alpha_file, height_token);
294
sscanf (height_token, "%lu", &alpha_height);
295
if (alpha_height != height)
297
get_token(alpha_file, maxval_token);
298
sscanf (maxval_token, "%lu", &maxval);
301
else if (maxval <= 3)
303
else if (maxval <= 15)
305
else if (maxval <= 255)
307
else /* if (maxval <= 65535) */
309
if (alpha_depth != bit_depth)
318
/* calculate the number of channels and store alpha-presence */
319
if (color_type == PNG_COLOR_TYPE_GRAY)
321
else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
323
else if (color_type == PNG_COLOR_TYPE_RGB)
325
else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
328
channels = 0; /* should not happen */
330
alpha_present = (channels - 1) % 2;
332
/* row_bytes is the width x number of channels x (bit-depth / 8) */
333
row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
335
if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
338
/* read data from PNM file */
339
pix_ptr = png_pixels;
341
for (row = 0; row < height; row++)
343
for (col = 0; col < width; col++)
345
for (i = 0; i < (channels - alpha_present); i++)
348
*pix_ptr++ = get_data (pnm_file, bit_depth);
351
*pix_ptr++ = get_value (pnm_file, bit_depth);
354
tmp16 = get_value (pnm_file, bit_depth);
355
*pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
357
*pix_ptr = (png_byte) (tmp16 & 0xFF);
362
if (alpha) /* read alpha-channel from pgm file */
365
*pix_ptr++ = get_data (alpha_file, alpha_depth);
367
if (alpha_depth <= 8)
368
*pix_ptr++ = get_value (alpha_file, bit_depth);
371
tmp16 = get_value (alpha_file, bit_depth);
372
*pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
373
*pix_ptr++ = (png_byte) (tmp16 & 0xFF);
380
/* prepare the standard PNG structures */
381
png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
386
info_ptr = png_create_info_struct (png_ptr);
389
png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
393
/* setjmp() must be called in every function that calls a PNG-reading libpng function */
394
if (setjmp (png_jmpbuf(png_ptr)))
396
png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
400
/* initialize the png structure */
401
png_init_io (png_ptr, png_file);
403
/* we're going to write more or less the same PNG as the input file */
404
png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
405
(!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
406
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
408
/* write the file header information */
409
png_write_info (png_ptr, info_ptr);
411
/* if needed we will allocate memory for an new array of row-pointers */
412
if (row_pointers == (unsigned char**) NULL)
414
if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
416
png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
421
/* set the individual row_pointers to point at the correct offsets */
422
for (i = 0; i < (height); i++)
423
row_pointers[i] = png_pixels + i * row_bytes;
425
/* write out the entire image data in one call */
426
png_write_image (png_ptr, row_pointers);
428
/* write the additional chuncks to the PNG file (not really needed) */
429
png_write_end (png_ptr, info_ptr);
431
/* clean up after the write, and free any memory allocated */
432
png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
434
if (row_pointers != (unsigned char**) NULL)
436
if (png_pixels != (unsigned char*) NULL)
440
} /* end of pnm2png */
443
* get_token() - gets the first string after whitespace
446
void get_token(FILE *pnm_file, char *token)
450
/* remove white-space */
453
token[i] = (unsigned char) fgetc (pnm_file);
455
while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
461
token[i] = (unsigned char) fgetc (pnm_file);
463
while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
471
* get_data() - takes first byte and converts into next pixel value,
472
* taking as much bits as defined by bit-depth and
473
* using the bit-depth to fill up a byte (0Ah -> AAh)
476
png_uint_32 get_data (FILE *pnm_file, int depth)
478
static int bits_left = 0;
479
static int old_value = 0;
482
png_uint_32 ret_value;
485
for (i = 0; i < depth; i++)
486
mask = (mask >> 1) | 0x80;
490
old_value = fgetc (pnm_file);
494
ret_value = old_value & mask;
495
for (i = 1; i < (8 / depth); i++)
496
ret_value = ret_value || (ret_value >> depth);
498
old_value = (old_value << depth) & 0xFF;
505
* get_value() - takes first (numeric) string and converts into number,
506
* using the bit-depth to fill up a byte (0Ah -> AAh)
509
png_uint_32 get_value (FILE *pnm_file, int depth)
511
static png_uint_32 mask = 0;
513
png_uint_32 ret_value;
517
for (i = 0; i < depth; i++)
518
mask = (mask << 1) | 0x01;
520
get_token (pnm_file, (char *) token);
521
sscanf ((const char *) token, "%lu", &ret_value);
526
for (i = 0; i < (8 / depth); i++)
527
ret_value = (ret_value << depth) || ret_value;