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- Committer: Package Import Robot
- Author(s): Alexandros Frantzis
- Date: 2011-09-22 11:32:17 UTC
- mfrom: (1.1.3 upstream)
- Revision ID: package-import@ubuntu.com-20110922113217-wvok1qgruexari8d
Tags: 2011.09-0ubuntu1
* New upstream release 2011.09.
* debian/control:
- Start the description of the glmark2-data package with
a lowercase letter.
* debian/control:
- Start the description of the glmark2-data package with
a lowercase letter.
- files added:
- INSTALL.android
- android
- android/assets
- android/jni
- android/jni/src
- android/res
- android/res/values
- android/src
- android/src/org
- android/src/org/linaro
- android/src/org/linaro/glmark2
- src/libpng
- files modified:
- NEWS
added
removed
src/libpng/pngrtran.c
1
2
/* pngrtran.c - transforms the data in a row for PNG readers
3
*
4
* Last changed in libpng 1.2.45 [July 7, 2011]
5
* Copyright (c) 1998-2011 Glenn Randers-Pehrson
6
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
8
*
9
* This code is released under the libpng license.
10
* For conditions of distribution and use, see the disclaimer
11
* and license in png.h
12
*
13
* This file contains functions optionally called by an application
14
* in order to tell libpng how to handle data when reading a PNG.
15
* Transformations that are used in both reading and writing are
16
* in pngtrans.c.
17
*/
18
19
#define PNG_INTERNAL
20
#define PNG_NO_PEDANTIC_WARNINGS
21
#include "png.h"
22
#ifdef PNG_READ_SUPPORTED
23
24
/* Set the action on getting a CRC error for an ancillary or critical chunk. */
25
void PNGAPI
26
png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
27
{
28
png_debug(1, "in png_set_crc_action");
29
30
if (png_ptr == NULL)
31
return;
32
33
/* Tell libpng how we react to CRC errors in critical chunks */
34
switch (crit_action)
35
{
36
case PNG_CRC_NO_CHANGE: /* Leave setting as is */
37
break;
38
39
case PNG_CRC_WARN_USE: /* Warn/use data */
40
png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
41
png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
42
break;
43
44
case PNG_CRC_QUIET_USE: /* Quiet/use data */
45
png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
46
png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
47
PNG_FLAG_CRC_CRITICAL_IGNORE;
48
break;
49
50
case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
51
png_warning(png_ptr,
52
"Can't discard critical data on CRC error.");
53
case PNG_CRC_ERROR_QUIT: /* Error/quit */
54
55
case PNG_CRC_DEFAULT:
56
default:
57
png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
58
break;
59
}
60
61
/* Tell libpng how we react to CRC errors in ancillary chunks */
62
switch (ancil_action)
63
{
64
case PNG_CRC_NO_CHANGE: /* Leave setting as is */
65
break;
66
67
case PNG_CRC_WARN_USE: /* Warn/use data */
68
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
69
png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
70
break;
71
72
case PNG_CRC_QUIET_USE: /* Quiet/use data */
73
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
74
png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
75
PNG_FLAG_CRC_ANCILLARY_NOWARN;
76
break;
77
78
case PNG_CRC_ERROR_QUIT: /* Error/quit */
79
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
80
png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
81
break;
82
83
case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
84
85
case PNG_CRC_DEFAULT:
86
default:
87
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
88
break;
89
}
90
}
91
92
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
93
defined(PNG_FLOATING_POINT_SUPPORTED)
94
/* Handle alpha and tRNS via a background color */
95
void PNGAPI
96
png_set_background(png_structp png_ptr,
97
png_color_16p background_color, int background_gamma_code,
98
int need_expand, double background_gamma)
99
{
100
png_debug(1, "in png_set_background");
101
102
if (png_ptr == NULL)
103
return;
104
if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
105
{
106
png_warning(png_ptr, "Application must supply a known background gamma");
107
return;
108
}
109
110
png_ptr->transformations |= PNG_BACKGROUND;
111
png_memcpy(&(png_ptr->background), background_color,
112
png_sizeof(png_color_16));
113
png_ptr->background_gamma = (float)background_gamma;
114
png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
115
png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
116
}
117
#endif
118
119
#ifdef PNG_READ_16_TO_8_SUPPORTED
120
/* Strip 16 bit depth files to 8 bit depth */
121
void PNGAPI
122
png_set_strip_16(png_structp png_ptr)
123
{
124
png_debug(1, "in png_set_strip_16");
125
126
if (png_ptr == NULL)
127
return;
128
png_ptr->transformations |= PNG_16_TO_8;
129
}
130
#endif
131
132
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
133
void PNGAPI
134
png_set_strip_alpha(png_structp png_ptr)
135
{
136
png_debug(1, "in png_set_strip_alpha");
137
138
if (png_ptr == NULL)
139
return;
140
png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
141
}
142
#endif
143
144
#ifdef PNG_READ_DITHER_SUPPORTED
145
/* Dither file to 8 bit. Supply a palette, the current number
146
* of elements in the palette, the maximum number of elements
147
* allowed, and a histogram if possible. If the current number
148
* of colors is greater then the maximum number, the palette will be
149
* modified to fit in the maximum number. "full_dither" indicates
150
* whether we need a dithering cube set up for RGB images, or if we
151
* simply are reducing the number of colors in a paletted image.
152
*/
153
154
typedef struct png_dsort_struct
155
{
156
struct png_dsort_struct FAR * next;
157
png_byte left;
158
png_byte right;
159
} png_dsort;
160
typedef png_dsort FAR * png_dsortp;
161
typedef png_dsort FAR * FAR * png_dsortpp;
162
163
void PNGAPI
164
png_set_dither(png_structp png_ptr, png_colorp palette,
165
int num_palette, int maximum_colors, png_uint_16p histogram,
166
int full_dither)
167
{
168
png_debug(1, "in png_set_dither");
169
170
if (png_ptr == NULL)
171
return;
172
png_ptr->transformations |= PNG_DITHER;
173
174
if (!full_dither)
175
{
176
int i;
177
178
png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
179
(png_uint_32)(num_palette * png_sizeof(png_byte)));
180
for (i = 0; i < num_palette; i++)
181
png_ptr->dither_index[i] = (png_byte)i;
182
}
183
184
if (num_palette > maximum_colors)
185
{
186
if (histogram != NULL)
187
{
188
/* This is easy enough, just throw out the least used colors.
189
* Perhaps not the best solution, but good enough.
190
*/
191
192
int i;
193
194
/* Initialize an array to sort colors */
195
png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
196
(png_uint_32)(num_palette * png_sizeof(png_byte)));
197
198
/* Initialize the dither_sort array */
199
for (i = 0; i < num_palette; i++)
200
png_ptr->dither_sort[i] = (png_byte)i;
201
202
/* Find the least used palette entries by starting a
203
* bubble sort, and running it until we have sorted
204
* out enough colors. Note that we don't care about
205
* sorting all the colors, just finding which are
206
* least used.
207
*/
208
209
for (i = num_palette - 1; i >= maximum_colors; i--)
210
{
211
int done; /* To stop early if the list is pre-sorted */
212
int j;
213
214
done = 1;
215
for (j = 0; j < i; j++)
216
{
217
if (histogram[png_ptr->dither_sort[j]]
218
< histogram[png_ptr->dither_sort[j + 1]])
219
{
220
png_byte t;
221
222
t = png_ptr->dither_sort[j];
223
png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
224
png_ptr->dither_sort[j + 1] = t;
225
done = 0;
226
}
227
}
228
if (done)
229
break;
230
}
231
232
/* Swap the palette around, and set up a table, if necessary */
233
if (full_dither)
234
{
235
int j = num_palette;
236
237
/* Put all the useful colors within the max, but don't
238
* move the others.
239
*/
240
for (i = 0; i < maximum_colors; i++)
241
{
242
if ((int)png_ptr->dither_sort[i] >= maximum_colors)
243
{
244
do
245
j--;
246
while ((int)png_ptr->dither_sort[j] >= maximum_colors);
247
palette[i] = palette[j];
248
}
249
}
250
}
251
else
252
{
253
int j = num_palette;
254
255
/* Move all the used colors inside the max limit, and
256
* develop a translation table.
257
*/
258
for (i = 0; i < maximum_colors; i++)
259
{
260
/* Only move the colors we need to */
261
if ((int)png_ptr->dither_sort[i] >= maximum_colors)
262
{
263
png_color tmp_color;
264
265
do
266
j--;
267
while ((int)png_ptr->dither_sort[j] >= maximum_colors);
268
269
tmp_color = palette[j];
270
palette[j] = palette[i];
271
palette[i] = tmp_color;
272
/* Indicate where the color went */
273
png_ptr->dither_index[j] = (png_byte)i;
274
png_ptr->dither_index[i] = (png_byte)j;
275
}
276
}
277
278
/* Find closest color for those colors we are not using */
279
for (i = 0; i < num_palette; i++)
280
{
281
if ((int)png_ptr->dither_index[i] >= maximum_colors)
282
{
283
int min_d, k, min_k, d_index;
284
285
/* Find the closest color to one we threw out */
286
d_index = png_ptr->dither_index[i];
287
min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
288
for (k = 1, min_k = 0; k < maximum_colors; k++)
289
{
290
int d;
291
292
d = PNG_COLOR_DIST(palette[d_index], palette[k]);
293
294
if (d < min_d)
295
{
296
min_d = d;
297
min_k = k;
298
}
299
}
300
/* Point to closest color */
301
png_ptr->dither_index[i] = (png_byte)min_k;
302
}
303
}
304
}
305
png_free(png_ptr, png_ptr->dither_sort);
306
png_ptr->dither_sort = NULL;
307
}
308
else
309
{
310
/* This is much harder to do simply (and quickly). Perhaps
311
* we need to go through a median cut routine, but those
312
* don't always behave themselves with only a few colors
313
* as input. So we will just find the closest two colors,
314
* and throw out one of them (chosen somewhat randomly).
315
* [We don't understand this at all, so if someone wants to
316
* work on improving it, be our guest - AED, GRP]
317
*/
318
int i;
319
int max_d;
320
int num_new_palette;
321
png_dsortp t;
322
png_dsortpp hash;
323
324
t = NULL;
325
326
/* Initialize palette index arrays */
327
png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
328
(png_uint_32)(num_palette * png_sizeof(png_byte)));
329
png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
330
(png_uint_32)(num_palette * png_sizeof(png_byte)));
331
332
/* Initialize the sort array */
333
for (i = 0; i < num_palette; i++)
334
{
335
png_ptr->index_to_palette[i] = (png_byte)i;
336
png_ptr->palette_to_index[i] = (png_byte)i;
337
}
338
339
hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
340
png_sizeof(png_dsortp)));
341
342
num_new_palette = num_palette;
343
344
/* Initial wild guess at how far apart the farthest pixel
345
* pair we will be eliminating will be. Larger
346
* numbers mean more areas will be allocated, Smaller
347
* numbers run the risk of not saving enough data, and
348
* having to do this all over again.
349
*
350
* I have not done extensive checking on this number.
351
*/
352
max_d = 96;
353
354
while (num_new_palette > maximum_colors)
355
{
356
for (i = 0; i < num_new_palette - 1; i++)
357
{
358
int j;
359
360
for (j = i + 1; j < num_new_palette; j++)
361
{
362
int d;
363
364
d = PNG_COLOR_DIST(palette[i], palette[j]);
365
366
if (d <= max_d)
367
{
368
369
t = (png_dsortp)png_malloc_warn(png_ptr,
370
(png_uint_32)(png_sizeof(png_dsort)));
371
if (t == NULL)
372
break;
373
t->next = hash[d];
374
t->left = (png_byte)i;
375
t->right = (png_byte)j;
376
hash[d] = t;
377
}
378
}
379
if (t == NULL)
380
break;
381
}
382
383
if (t != NULL)
384
for (i = 0; i <= max_d; i++)
385
{
386
if (hash[i] != NULL)
387
{
388
png_dsortp p;
389
390
for (p = hash[i]; p; p = p->next)
391
{
392
if ((int)png_ptr->index_to_palette[p->left]
393
< num_new_palette &&
394
(int)png_ptr->index_to_palette[p->right]
395
< num_new_palette)
396
{
397
int j, next_j;
398
399
if (num_new_palette & 0x01)
400
{
401
j = p->left;
402
next_j = p->right;
403
}
404
else
405
{
406
j = p->right;
407
next_j = p->left;
408
}
409
410
num_new_palette--;
411
palette[png_ptr->index_to_palette[j]]
412
= palette[num_new_palette];
413
if (!full_dither)
414
{
415
int k;
416
417
for (k = 0; k < num_palette; k++)
418
{
419
if (png_ptr->dither_index[k] ==
420
png_ptr->index_to_palette[j])
421
png_ptr->dither_index[k] =
422
png_ptr->index_to_palette[next_j];
423
if ((int)png_ptr->dither_index[k] ==
424
num_new_palette)
425
png_ptr->dither_index[k] =
426
png_ptr->index_to_palette[j];
427
}
428
}
429
430
png_ptr->index_to_palette[png_ptr->palette_to_index
431
[num_new_palette]] = png_ptr->index_to_palette[j];
432
png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
433
= png_ptr->palette_to_index[num_new_palette];
434
435
png_ptr->index_to_palette[j] =
436
(png_byte)num_new_palette;
437
png_ptr->palette_to_index[num_new_palette] =
438
(png_byte)j;
439
}
440
if (num_new_palette <= maximum_colors)
441
break;
442
}
443
if (num_new_palette <= maximum_colors)
444
break;
445
}
446
}
447
448
for (i = 0; i < 769; i++)
449
{
450
if (hash[i] != NULL)
451
{
452
png_dsortp p = hash[i];
453
while (p)
454
{
455
t = p->next;
456
png_free(png_ptr, p);
457
p = t;
458
}
459
}
460
hash[i] = 0;
461
}
462
max_d += 96;
463
}
464
png_free(png_ptr, hash);
465
png_free(png_ptr, png_ptr->palette_to_index);
466
png_free(png_ptr, png_ptr->index_to_palette);
467
png_ptr->palette_to_index = NULL;
468
png_ptr->index_to_palette = NULL;
469
}
470
num_palette = maximum_colors;
471
}
472
if (png_ptr->palette == NULL)
473
{
474
png_ptr->palette = palette;
475
}
476
png_ptr->num_palette = (png_uint_16)num_palette;
477
478
if (full_dither)
479
{
480
int i;
481
png_bytep distance;
482
int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
483
PNG_DITHER_BLUE_BITS;
484
int num_red = (1 << PNG_DITHER_RED_BITS);
485
int num_green = (1 << PNG_DITHER_GREEN_BITS);
486
int num_blue = (1 << PNG_DITHER_BLUE_BITS);
487
png_size_t num_entries = ((png_size_t)1 << total_bits);
488
489
png_ptr->palette_lookup = (png_bytep )png_calloc(png_ptr,
490
(png_uint_32)(num_entries * png_sizeof(png_byte)));
491
492
distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
493
png_sizeof(png_byte)));
494
png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
495
496
for (i = 0; i < num_palette; i++)
497
{
498
int ir, ig, ib;
499
int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
500
int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
501
int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
502
503
for (ir = 0; ir < num_red; ir++)
504
{
505
/* int dr = abs(ir - r); */
506
int dr = ((ir > r) ? ir - r : r - ir);
507
int index_r = (ir << (PNG_DITHER_BLUE_BITS +
508
PNG_DITHER_GREEN_BITS));
509
510
for (ig = 0; ig < num_green; ig++)
511
{
512
/* int dg = abs(ig - g); */
513
int dg = ((ig > g) ? ig - g : g - ig);
514
int dt = dr + dg;
515
int dm = ((dr > dg) ? dr : dg);
516
int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);
517
518
for (ib = 0; ib < num_blue; ib++)
519
{
520
int d_index = index_g | ib;
521
/* int db = abs(ib - b); */
522
int db = ((ib > b) ? ib - b : b - ib);
523
int dmax = ((dm > db) ? dm : db);
524
int d = dmax + dt + db;
525
526
if (d < (int)distance[d_index])
527
{
528
distance[d_index] = (png_byte)d;
529
png_ptr->palette_lookup[d_index] = (png_byte)i;
530
}
531
}
532
}
533
}
534
}
535
536
png_free(png_ptr, distance);
537
}
538
}
539
#endif
540
541
#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
542
/* Transform the image from the file_gamma to the screen_gamma. We
543
* only do transformations on images where the file_gamma and screen_gamma
544
* are not close reciprocals, otherwise it slows things down slightly, and
545
* also needlessly introduces small errors.
546
*
547
* We will turn off gamma transformation later if no semitransparent entries
548
* are present in the tRNS array for palette images. We can't do it here
549
* because we don't necessarily have the tRNS chunk yet.
550
*/
551
void PNGAPI
552
png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
553
{
554
png_debug(1, "in png_set_gamma");
555
556
if (png_ptr == NULL)
557
return;
558
559
if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
560
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
561
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
562
png_ptr->transformations |= PNG_GAMMA;
563
png_ptr->gamma = (float)file_gamma;
564
png_ptr->screen_gamma = (float)scrn_gamma;
565
}
566
#endif
567
568
#ifdef PNG_READ_EXPAND_SUPPORTED
569
/* Expand paletted images to RGB, expand grayscale images of
570
* less than 8-bit depth to 8-bit depth, and expand tRNS chunks
571
* to alpha channels.
572
*/
573
void PNGAPI
574
png_set_expand(png_structp png_ptr)
575
{
576
png_debug(1, "in png_set_expand");
577
578
if (png_ptr == NULL)
579
return;
580
581
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
582
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
583
}
584
585
/* GRR 19990627: the following three functions currently are identical
586
* to png_set_expand(). However, it is entirely reasonable that someone
587
* might wish to expand an indexed image to RGB but *not* expand a single,
588
* fully transparent palette entry to a full alpha channel--perhaps instead
589
* convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
590
* the transparent color with a particular RGB value, or drop tRNS entirely.
591
* IOW, a future version of the library may make the transformations flag
592
* a bit more fine-grained, with separate bits for each of these three
593
* functions.
594
*
595
* More to the point, these functions make it obvious what libpng will be
596
* doing, whereas "expand" can (and does) mean any number of things.
597
*
598
* GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
599
* to expand only the sample depth but not to expand the tRNS to alpha
600
* and its name was changed to png_set_expand_gray_1_2_4_to_8().
601
*/
602
603
/* Expand paletted images to RGB. */
604
void PNGAPI
605
png_set_palette_to_rgb(png_structp png_ptr)
606
{
607
png_debug(1, "in png_set_palette_to_rgb");
608
609
if (png_ptr == NULL)
610
return;
611
612
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
613
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
614
}
615
616
#ifndef PNG_1_0_X
617
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
618
void PNGAPI
619
png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
620
{
621
png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
622
623
if (png_ptr == NULL)
624
return;
625
626
png_ptr->transformations |= PNG_EXPAND;
627
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
628
}
629
#endif
630
631
#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
632
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
633
/* Deprecated as of libpng-1.2.9 */
634
void PNGAPI
635
png_set_gray_1_2_4_to_8(png_structp png_ptr)
636
{
637
png_debug(1, "in png_set_gray_1_2_4_to_8");
638
639
if (png_ptr == NULL)
640
return;
641
642
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
643
}
644
#endif
645
646
647
/* Expand tRNS chunks to alpha channels. */
648
void PNGAPI
649
png_set_tRNS_to_alpha(png_structp png_ptr)
650
{
651
png_debug(1, "in png_set_tRNS_to_alpha");
652
653
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
654
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
655
}
656
#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
657
658
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
659
void PNGAPI
660
png_set_gray_to_rgb(png_structp png_ptr)
661
{
662
png_debug(1, "in png_set_gray_to_rgb");
663
664
png_ptr->transformations |= PNG_GRAY_TO_RGB;
665
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
666
}
667
#endif
668
669
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
670
#ifdef PNG_FLOATING_POINT_SUPPORTED
671
/* Convert a RGB image to a grayscale of the same width. This allows us,
672
* for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
673
*/
674
675
void PNGAPI
676
png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
677
double green)
678
{
679
int red_fixed, green_fixed;
680
if (png_ptr == NULL)
681
return;
682
if (red > 21474.83647 || red < -21474.83648 ||
683
green > 21474.83647 || green < -21474.83648)
684
{
685
png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
686
red_fixed = -1;
687
green_fixed = -1;
688
}
689
else
690
{
691
red_fixed = (int)((float)red*100000.0 + 0.5);
692
green_fixed = (int)((float)green*100000.0 + 0.5);
693
}
694
png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
695
}
696
#endif
697
698
void PNGAPI
699
png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
700
png_fixed_point red, png_fixed_point green)
701
{
702
png_debug(1, "in png_set_rgb_to_gray");
703
704
if (png_ptr == NULL)
705
return;
706
707
switch(error_action)
708
{
709
case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
710
break;
711
712
case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
713
break;
714
715
case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
716
}
717
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
718
#ifdef PNG_READ_EXPAND_SUPPORTED
719
png_ptr->transformations |= PNG_EXPAND;
720
#else
721
{
722
png_warning(png_ptr,
723
"Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
724
png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
725
}
726
#endif
727
{
728
png_uint_16 red_int, green_int;
729
if (red < 0 || green < 0)
730
{
731
red_int = 6968; /* .212671 * 32768 + .5 */
732
green_int = 23434; /* .715160 * 32768 + .5 */
733
}
734
else if (red + green < 100000L)
735
{
736
red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
737
green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
738
}
739
else
740
{
741
png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
742
red_int = 6968;
743
green_int = 23434;
744
}
745
png_ptr->rgb_to_gray_red_coeff = red_int;
746
png_ptr->rgb_to_gray_green_coeff = green_int;
747
png_ptr->rgb_to_gray_blue_coeff =
748
(png_uint_16)(32768 - red_int - green_int);
749
}
750
}
751
#endif
752
753
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
754
defined(PNG_LEGACY_SUPPORTED) || \
755
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
756
void PNGAPI
757
png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
758
read_user_transform_fn)
759
{
760
png_debug(1, "in png_set_read_user_transform_fn");
761
762
if (png_ptr == NULL)
763
return;
764
765
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
766
png_ptr->transformations |= PNG_USER_TRANSFORM;
767
png_ptr->read_user_transform_fn = read_user_transform_fn;
768
#endif
769
#ifdef PNG_LEGACY_SUPPORTED
770
if (read_user_transform_fn)
771
png_warning(png_ptr,
772
"This version of libpng does not support user transforms");
773
#endif
774
}
775
#endif
776
777
/* Initialize everything needed for the read. This includes modifying
778
* the palette.
779
*/
780
void /* PRIVATE */
781
png_init_read_transformations(png_structp png_ptr)
782
{
783
png_debug(1, "in png_init_read_transformations");
784
785
#ifdef PNG_USELESS_TESTS_SUPPORTED
786
if (png_ptr != NULL)
787
#endif
788
{
789
#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
790
defined(PNG_READ_SHIFT_SUPPORTED) || \
791
defined(PNG_READ_GAMMA_SUPPORTED)
792
int color_type = png_ptr->color_type;
793
#endif
794
795
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
796
797
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
798
/* Detect gray background and attempt to enable optimization
799
* for gray --> RGB case
800
*
801
* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
802
* RGB_ALPHA (in which case need_expand is superfluous anyway), the
803
* background color might actually be gray yet not be flagged as such.
804
* This is not a problem for the current code, which uses
805
* PNG_BACKGROUND_IS_GRAY only to decide when to do the
806
* png_do_gray_to_rgb() transformation.
807
*/
808
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
809
!(color_type & PNG_COLOR_MASK_COLOR))
810
{
811
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
812
} else if ((png_ptr->transformations & PNG_BACKGROUND) &&
813
!(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
814
(png_ptr->transformations & PNG_GRAY_TO_RGB) &&
815
png_ptr->background.red == png_ptr->background.green &&
816
png_ptr->background.red == png_ptr->background.blue)
817
{
818
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
819
png_ptr->background.gray = png_ptr->background.red;
820
}
821
#endif
822
823
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
824
(png_ptr->transformations & PNG_EXPAND))
825
{
826
if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
827
{
828
/* Expand background and tRNS chunks */
829
switch (png_ptr->bit_depth)
830
{
831
case 1:
832
png_ptr->background.gray *= (png_uint_16)0xff;
833
png_ptr->background.red = png_ptr->background.green
834
= png_ptr->background.blue = png_ptr->background.gray;
835
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
836
{
837
png_ptr->trans_values.gray *= (png_uint_16)0xff;
838
png_ptr->trans_values.red = png_ptr->trans_values.green
839
= png_ptr->trans_values.blue = png_ptr->trans_values.gray;
840
}
841
break;
842
843
case 2:
844
png_ptr->background.gray *= (png_uint_16)0x55;
845
png_ptr->background.red = png_ptr->background.green
846
= png_ptr->background.blue = png_ptr->background.gray;
847
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
848
{
849
png_ptr->trans_values.gray *= (png_uint_16)0x55;
850
png_ptr->trans_values.red = png_ptr->trans_values.green
851
= png_ptr->trans_values.blue = png_ptr->trans_values.gray;
852
}
853
break;
854
855
case 4:
856
png_ptr->background.gray *= (png_uint_16)0x11;
857
png_ptr->background.red = png_ptr->background.green
858
= png_ptr->background.blue = png_ptr->background.gray;
859
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
860
{
861
png_ptr->trans_values.gray *= (png_uint_16)0x11;
862
png_ptr->trans_values.red = png_ptr->trans_values.green
863
= png_ptr->trans_values.blue = png_ptr->trans_values.gray;
864
}
865
break;
866
867
case 8:
868
869
case 16:
870
png_ptr->background.red = png_ptr->background.green
871
= png_ptr->background.blue = png_ptr->background.gray;
872
break;
873
}
874
}
875
else if (color_type == PNG_COLOR_TYPE_PALETTE)
876
{
877
png_ptr->background.red =
878
png_ptr->palette[png_ptr->background.index].red;
879
png_ptr->background.green =
880
png_ptr->palette[png_ptr->background.index].green;
881
png_ptr->background.blue =
882
png_ptr->palette[png_ptr->background.index].blue;
883
884
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
885
if (png_ptr->transformations & PNG_INVERT_ALPHA)
886
{
887
#ifdef PNG_READ_EXPAND_SUPPORTED
888
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
889
#endif
890
{
891
/* Invert the alpha channel (in tRNS) unless the pixels are
892
* going to be expanded, in which case leave it for later
893
*/
894
int i, istop;
895
istop=(int)png_ptr->num_trans;
896
for (i=0; i<istop; i++)
897
png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
898
}
899
}
900
#endif
901
902
}
903
}
904
#endif
905
906
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
907
png_ptr->background_1 = png_ptr->background;
908
#endif
909
#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
910
911
if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
912
&& (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
913
< PNG_GAMMA_THRESHOLD))
914
{
915
int i, k;
916
k=0;
917
for (i=0; i<png_ptr->num_trans; i++)
918
{
919
if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
920
k=1; /* Partial transparency is present */
921
}
922
if (k == 0)
923
png_ptr->transformations &= ~PNG_GAMMA;
924
}
925
926
if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
927
png_ptr->gamma != 0.0)
928
{
929
png_build_gamma_table(png_ptr);
930
931
#ifdef PNG_READ_BACKGROUND_SUPPORTED
932
if (png_ptr->transformations & PNG_BACKGROUND)
933
{
934
if (color_type == PNG_COLOR_TYPE_PALETTE)
935
{
936
/* Could skip if no transparency */
937
png_color back, back_1;
938
png_colorp palette = png_ptr->palette;
939
int num_palette = png_ptr->num_palette;
940
int i;
941
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
942
{
943
back.red = png_ptr->gamma_table[png_ptr->background.red];
944
back.green = png_ptr->gamma_table[png_ptr->background.green];
945
back.blue = png_ptr->gamma_table[png_ptr->background.blue];
946
947
back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
948
back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
949
back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
950
}
951
else
952
{
953
double g, gs;
954
955
switch (png_ptr->background_gamma_type)
956
{
957
case PNG_BACKGROUND_GAMMA_SCREEN:
958
g = (png_ptr->screen_gamma);
959
gs = 1.0;
960
break;
961
962
case PNG_BACKGROUND_GAMMA_FILE:
963
g = 1.0 / (png_ptr->gamma);
964
gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
965
break;
966
967
case PNG_BACKGROUND_GAMMA_UNIQUE:
968
g = 1.0 / (png_ptr->background_gamma);
969
gs = 1.0 / (png_ptr->background_gamma *
970
png_ptr->screen_gamma);
971
break;
972
default:
973
g = 1.0; /* back_1 */
974
gs = 1.0; /* back */
975
}
976
977
if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
978
{
979
back.red = (png_byte)png_ptr->background.red;
980
back.green = (png_byte)png_ptr->background.green;
981
back.blue = (png_byte)png_ptr->background.blue;
982
}
983
else
984
{
985
back.red = (png_byte)(pow(
986
(double)png_ptr->background.red/255, gs) * 255.0 + .5);
987
back.green = (png_byte)(pow(
988
(double)png_ptr->background.green/255, gs) * 255.0
989
+ .5);
990
back.blue = (png_byte)(pow(
991
(double)png_ptr->background.blue/255, gs) * 255.0 + .5);
992
}
993
994
back_1.red = (png_byte)(pow(
995
(double)png_ptr->background.red/255, g) * 255.0 + .5);
996
back_1.green = (png_byte)(pow(
997
(double)png_ptr->background.green/255, g) * 255.0 + .5);
998
back_1.blue = (png_byte)(pow(
999
(double)png_ptr->background.blue/255, g) * 255.0 + .5);
1000
}
1001
for (i = 0; i < num_palette; i++)
1002
{
1003
if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
1004
{
1005
if (png_ptr->trans[i] == 0)
1006
{
1007
palette[i] = back;
1008
}
1009
else /* if (png_ptr->trans[i] != 0xff) */
1010
{
1011
png_byte v, w;
1012
1013
v = png_ptr->gamma_to_1[palette[i].red];
1014
png_composite(w, v, png_ptr->trans[i], back_1.red);
1015
palette[i].red = png_ptr->gamma_from_1[w];
1016
1017
v = png_ptr->gamma_to_1[palette[i].green];
1018
png_composite(w, v, png_ptr->trans[i], back_1.green);
1019
palette[i].green = png_ptr->gamma_from_1[w];
1020
1021
v = png_ptr->gamma_to_1[palette[i].blue];
1022
png_composite(w, v, png_ptr->trans[i], back_1.blue);
1023
palette[i].blue = png_ptr->gamma_from_1[w];
1024
}
1025
}
1026
else
1027
{
1028
palette[i].red = png_ptr->gamma_table[palette[i].red];
1029
palette[i].green = png_ptr->gamma_table[palette[i].green];
1030
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
1031
}
1032
}
1033
/* Prevent the transformations being done again, and make sure
1034
* that the now spurious alpha channel is stripped - the code
1035
* has just reduced background composition and gamma correction
1036
* to a simple alpha channel strip.
1037
*/
1038
png_ptr->transformations &= ~PNG_BACKGROUND;
1039
png_ptr->transformations &= ~PNG_GAMMA;
1040
png_ptr->transformations |= PNG_STRIP_ALPHA;
1041
}
1042
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
1043
else
1044
/* color_type != PNG_COLOR_TYPE_PALETTE */
1045
{
1046
double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);
1047
double g = 1.0;
1048
double gs = 1.0;
1049
1050
switch (png_ptr->background_gamma_type)
1051
{
1052
case PNG_BACKGROUND_GAMMA_SCREEN:
1053
g = (png_ptr->screen_gamma);
1054
gs = 1.0;
1055
break;
1056
1057
case PNG_BACKGROUND_GAMMA_FILE:
1058
g = 1.0 / (png_ptr->gamma);
1059
gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
1060
break;
1061
1062
case PNG_BACKGROUND_GAMMA_UNIQUE:
1063
g = 1.0 / (png_ptr->background_gamma);
1064
gs = 1.0 / (png_ptr->background_gamma *
1065
png_ptr->screen_gamma);
1066
break;
1067
}
1068
1069
png_ptr->background_1.gray = (png_uint_16)(pow(
1070
(double)png_ptr->background.gray / m, g) * m + .5);
1071
png_ptr->background.gray = (png_uint_16)(pow(
1072
(double)png_ptr->background.gray / m, gs) * m + .5);
1073
1074
if ((png_ptr->background.red != png_ptr->background.green) ||
1075
(png_ptr->background.red != png_ptr->background.blue) ||
1076
(png_ptr->background.red != png_ptr->background.gray))
1077
{
1078
/* RGB or RGBA with color background */
1079
png_ptr->background_1.red = (png_uint_16)(pow(
1080
(double)png_ptr->background.red / m, g) * m + .5);
1081
png_ptr->background_1.green = (png_uint_16)(pow(
1082
(double)png_ptr->background.green / m, g) * m + .5);
1083
png_ptr->background_1.blue = (png_uint_16)(pow(
1084
(double)png_ptr->background.blue / m, g) * m + .5);
1085
png_ptr->background.red = (png_uint_16)(pow(
1086
(double)png_ptr->background.red / m, gs) * m + .5);
1087
png_ptr->background.green = (png_uint_16)(pow(
1088
(double)png_ptr->background.green / m, gs) * m + .5);
1089
png_ptr->background.blue = (png_uint_16)(pow(
1090
(double)png_ptr->background.blue / m, gs) * m + .5);
1091
}
1092
else
1093
{
1094
/* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
1095
png_ptr->background_1.red = png_ptr->background_1.green
1096
= png_ptr->background_1.blue = png_ptr->background_1.gray;
1097
png_ptr->background.red = png_ptr->background.green
1098
= png_ptr->background.blue = png_ptr->background.gray;
1099
}
1100
}
1101
}
1102
else
1103
/* Transformation does not include PNG_BACKGROUND */
1104
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
1105
if (color_type == PNG_COLOR_TYPE_PALETTE)
1106
{
1107
png_colorp palette = png_ptr->palette;
1108
int num_palette = png_ptr->num_palette;
1109
int i;
1110
1111
for (i = 0; i < num_palette; i++)
1112
{
1113
palette[i].red = png_ptr->gamma_table[palette[i].red];
1114
palette[i].green = png_ptr->gamma_table[palette[i].green];
1115
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
1116
}
1117
1118
/* Done the gamma correction. */
1119
png_ptr->transformations &= ~PNG_GAMMA;
1120
}
1121
}
1122
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1123
else
1124
#endif
1125
#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
1126
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1127
/* No GAMMA transformation */
1128
if ((png_ptr->transformations & PNG_BACKGROUND) &&
1129
(color_type == PNG_COLOR_TYPE_PALETTE))
1130
{
1131
int i;
1132
int istop = (int)png_ptr->num_trans;
1133
png_color back;
1134
png_colorp palette = png_ptr->palette;
1135
1136
back.red = (png_byte)png_ptr->background.red;
1137
back.green = (png_byte)png_ptr->background.green;
1138
back.blue = (png_byte)png_ptr->background.blue;
1139
1140
for (i = 0; i < istop; i++)
1141
{
1142
if (png_ptr->trans[i] == 0)
1143
{
1144
palette[i] = back;
1145
}
1146
else if (png_ptr->trans[i] != 0xff)
1147
{
1148
/* The png_composite() macro is defined in png.h */
1149
png_composite(palette[i].red, palette[i].red,
1150
png_ptr->trans[i], back.red);
1151
png_composite(palette[i].green, palette[i].green,
1152
png_ptr->trans[i], back.green);
1153
png_composite(palette[i].blue, palette[i].blue,
1154
png_ptr->trans[i], back.blue);
1155
}
1156
}
1157
1158
/* Handled alpha, still need to strip the channel. */
1159
png_ptr->transformations &= ~PNG_BACKGROUND;
1160
png_ptr->transformations |= PNG_STRIP_ALPHA;
1161
}
1162
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
1163
1164
#ifdef PNG_READ_SHIFT_SUPPORTED
1165
if ((png_ptr->transformations & PNG_SHIFT) &&
1166
(color_type == PNG_COLOR_TYPE_PALETTE))
1167
{
1168
png_uint_16 i;
1169
png_uint_16 istop = png_ptr->num_palette;
1170
int sr = 8 - png_ptr->sig_bit.red;
1171
int sg = 8 - png_ptr->sig_bit.green;
1172
int sb = 8 - png_ptr->sig_bit.blue;
1173
1174
if (sr < 0 || sr > 8)
1175
sr = 0;
1176
if (sg < 0 || sg > 8)
1177
sg = 0;
1178
if (sb < 0 || sb > 8)
1179
sb = 0;
1180
for (i = 0; i < istop; i++)
1181
{
1182
png_ptr->palette[i].red >>= sr;
1183
png_ptr->palette[i].green >>= sg;
1184
png_ptr->palette[i].blue >>= sb;
1185
}
1186
}
1187
#endif /* PNG_READ_SHIFT_SUPPORTED */
1188
}
1189
#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
1190
&& !defined(PNG_READ_BACKGROUND_SUPPORTED)
1191
if (png_ptr)
1192
return;
1193
#endif
1194
}
1195
1196
/* Modify the info structure to reflect the transformations. The
1197
* info should be updated so a PNG file could be written with it,
1198
* assuming the transformations result in valid PNG data.
1199
*/
1200
void /* PRIVATE */
1201
png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
1202
{
1203
png_debug(1, "in png_read_transform_info");
1204
1205
#ifdef PNG_READ_EXPAND_SUPPORTED
1206
if (png_ptr->transformations & PNG_EXPAND)
1207
{
1208
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1209
{
1210
if (png_ptr->num_trans)
1211
info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
1212
else
1213
info_ptr->color_type = PNG_COLOR_TYPE_RGB;
1214
info_ptr->bit_depth = 8;
1215
info_ptr->num_trans = 0;
1216
}
1217
else
1218
{
1219
if (png_ptr->num_trans)
1220
{
1221
if (png_ptr->transformations & PNG_EXPAND_tRNS)
1222
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
1223
}
1224
if (info_ptr->bit_depth < 8)
1225
info_ptr->bit_depth = 8;
1226
info_ptr->num_trans = 0;
1227
}
1228
}
1229
#endif
1230
1231
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1232
if (png_ptr->transformations & PNG_BACKGROUND)
1233
{
1234
info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
1235
info_ptr->num_trans = 0;
1236
info_ptr->background = png_ptr->background;
1237
}
1238
#endif
1239
1240
#ifdef PNG_READ_GAMMA_SUPPORTED
1241
if (png_ptr->transformations & PNG_GAMMA)
1242
{
1243
#ifdef PNG_FLOATING_POINT_SUPPORTED
1244
info_ptr->gamma = png_ptr->gamma;
1245
#endif
1246
#ifdef PNG_FIXED_POINT_SUPPORTED
1247
info_ptr->int_gamma = png_ptr->int_gamma;
1248
#endif
1249
}
1250
#endif
1251
1252
#ifdef PNG_READ_16_TO_8_SUPPORTED
1253
if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
1254
info_ptr->bit_depth = 8;
1255
#endif
1256
1257
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1258
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
1259
info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
1260
#endif
1261
1262
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1263
if (png_ptr->transformations & PNG_RGB_TO_GRAY)
1264
info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
1265
#endif
1266
1267
#ifdef PNG_READ_DITHER_SUPPORTED
1268
if (png_ptr->transformations & PNG_DITHER)
1269
{
1270
if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
1271
(info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
1272
png_ptr->palette_lookup && info_ptr->bit_depth == 8)
1273
{
1274
info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
1275
}
1276
}
1277
#endif
1278
1279
#ifdef PNG_READ_PACK_SUPPORTED
1280
if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
1281
info_ptr->bit_depth = 8;
1282
#endif
1283
1284
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
1285
info_ptr->channels = 1;
1286
else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
1287
info_ptr->channels = 3;
1288
else
1289
info_ptr->channels = 1;
1290
1291
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1292
if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
1293
info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
1294
#endif
1295
1296
if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
1297
info_ptr->channels++;
1298
1299
#ifdef PNG_READ_FILLER_SUPPORTED
1300
/* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
1301
if ((png_ptr->transformations & PNG_FILLER) &&
1302
((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
1303
(info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
1304
{
1305
info_ptr->channels++;
1306
/* If adding a true alpha channel not just filler */
1307
#ifndef PNG_1_0_X
1308
if (png_ptr->transformations & PNG_ADD_ALPHA)
1309
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
1310
#endif
1311
}
1312
#endif
1313
1314
#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
1315
defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
1316
if (png_ptr->transformations & PNG_USER_TRANSFORM)
1317
{
1318
if (info_ptr->bit_depth < png_ptr->user_transform_depth)
1319
info_ptr->bit_depth = png_ptr->user_transform_depth;
1320
if (info_ptr->channels < png_ptr->user_transform_channels)
1321
info_ptr->channels = png_ptr->user_transform_channels;
1322
}
1323
#endif
1324
1325
info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
1326
info_ptr->bit_depth);
1327
1328
info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
1329
1330
#ifndef PNG_READ_EXPAND_SUPPORTED
1331
if (png_ptr)
1332
return;
1333
#endif
1334
}
1335
1336
/* Transform the row. The order of transformations is significant,
1337
* and is very touchy. If you add a transformation, take care to
1338
* decide how it fits in with the other transformations here.
1339
*/
1340
void /* PRIVATE */
1341
png_do_read_transformations(png_structp png_ptr)
1342
{
1343
png_debug(1, "in png_do_read_transformations");
1344
1345
if (png_ptr->row_buf == NULL)
1346
{
1347
#if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE)
1348
char msg[50];
1349
1350
png_snprintf2(msg, 50,
1351
"NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
1352
png_ptr->pass);
1353
png_error(png_ptr, msg);
1354
#else
1355
png_error(png_ptr, "NULL row buffer");
1356
#endif
1357
}
1358
#ifdef PNG_WARN_UNINITIALIZED_ROW
1359
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
1360
/* Application has failed to call either png_read_start_image()
1361
* or png_read_update_info() after setting transforms that expand
1362
* pixels. This check added to libpng-1.2.19
1363
*/
1364
#if (PNG_WARN_UNINITIALIZED_ROW==1)
1365
png_error(png_ptr, "Uninitialized row");
1366
#else
1367
png_warning(png_ptr, "Uninitialized row");
1368
#endif
1369
#endif
1370
1371
#ifdef PNG_READ_EXPAND_SUPPORTED
1372
if (png_ptr->transformations & PNG_EXPAND)
1373
{
1374
if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
1375
{
1376
png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
1377
png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
1378
}
1379
else
1380
{
1381
if (png_ptr->num_trans &&
1382
(png_ptr->transformations & PNG_EXPAND_tRNS))
1383
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
1384
&(png_ptr->trans_values));
1385
else
1386
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
1387
NULL);
1388
}
1389
}
1390
#endif
1391
1392
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
1393
if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
1394
png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
1395
PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
1396
#endif
1397
1398
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
1399
if (png_ptr->transformations & PNG_RGB_TO_GRAY)
1400
{
1401
int rgb_error =
1402
png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info),
1403
png_ptr->row_buf + 1);
1404
if (rgb_error)
1405
{
1406
png_ptr->rgb_to_gray_status=1;
1407
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
1408
PNG_RGB_TO_GRAY_WARN)
1409
png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
1410
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
1411
PNG_RGB_TO_GRAY_ERR)
1412
png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
1413
}
1414
}
1415
#endif
1416
1417
/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
1418
*
1419
* In most cases, the "simple transparency" should be done prior to doing
1420
* gray-to-RGB, or you will have to test 3x as many bytes to check if a
1421
* pixel is transparent. You would also need to make sure that the
1422
* transparency information is upgraded to RGB.
1423
*
1424
* To summarize, the current flow is:
1425
* - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
1426
* with background "in place" if transparent,
1427
* convert to RGB if necessary
1428
* - Gray + alpha -> composite with gray background and remove alpha bytes,
1429
* convert to RGB if necessary
1430
*
1431
* To support RGB backgrounds for gray images we need:
1432
* - Gray + simple transparency -> convert to RGB + simple transparency,
1433
* compare 3 or 6 bytes and composite with
1434
* background "in place" if transparent
1435
* (3x compare/pixel compared to doing
1436
* composite with gray bkgrnd)
1437
* - Gray + alpha -> convert to RGB + alpha, composite with background and
1438
* remove alpha bytes (3x float
1439
* operations/pixel compared with composite
1440
* on gray background)
1441
*
1442
* Greg's change will do this. The reason it wasn't done before is for
1443
* performance, as this increases the per-pixel operations. If we would check
1444
* in advance if the background was gray or RGB, and position the gray-to-RGB
1445
* transform appropriately, then it would save a lot of work/time.
1446
*/
1447
1448
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1449
/* If gray -> RGB, do so now only if background is non-gray; else do later
1450
* for performance reasons
1451
*/
1452
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
1453
!(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
1454
png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
1455
#endif
1456
1457
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1458
if ((png_ptr->transformations & PNG_BACKGROUND) &&
1459
((png_ptr->num_trans != 0 ) ||
1460
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
1461
png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
1462
&(png_ptr->trans_values), &(png_ptr->background)
1463
#ifdef PNG_READ_GAMMA_SUPPORTED
1464
, &(png_ptr->background_1),
1465
png_ptr->gamma_table, png_ptr->gamma_from_1,
1466
png_ptr->gamma_to_1, png_ptr->gamma_16_table,
1467
png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
1468
png_ptr->gamma_shift
1469
#endif
1470
);
1471
#endif
1472
1473
#ifdef PNG_READ_GAMMA_SUPPORTED
1474
if ((png_ptr->transformations & PNG_GAMMA) &&
1475
#ifdef PNG_READ_BACKGROUND_SUPPORTED
1476
!((png_ptr->transformations & PNG_BACKGROUND) &&
1477
((png_ptr->num_trans != 0) ||
1478
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
1479
#endif
1480
(png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
1481
png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
1482
png_ptr->gamma_table, png_ptr->gamma_16_table,
1483
png_ptr->gamma_shift);
1484
#endif
1485
1486
#ifdef PNG_READ_16_TO_8_SUPPORTED
1487
if (png_ptr->transformations & PNG_16_TO_8)
1488
png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
1489
#endif
1490
1491
#ifdef PNG_READ_DITHER_SUPPORTED
1492
if (png_ptr->transformations & PNG_DITHER)
1493
{
1494
png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
1495
png_ptr->palette_lookup, png_ptr->dither_index);
1496
if (png_ptr->row_info.rowbytes == (png_uint_32)0)
1497
png_error(png_ptr, "png_do_dither returned rowbytes=0");
1498
}
1499
#endif
1500
1501
#ifdef PNG_READ_INVERT_SUPPORTED
1502
if (png_ptr->transformations & PNG_INVERT_MONO)
1503
png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
1504
#endif
1505
1506
#ifdef PNG_READ_SHIFT_SUPPORTED
1507
if (png_ptr->transformations & PNG_SHIFT)
1508
png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
1509
&(png_ptr->shift));
1510
#endif
1511
1512
#ifdef PNG_READ_PACK_SUPPORTED
1513
if (png_ptr->transformations & PNG_PACK)
1514
png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
1515
#endif
1516
1517
#ifdef PNG_READ_BGR_SUPPORTED
1518
if (png_ptr->transformations & PNG_BGR)
1519
png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
1520
#endif
1521
1522
#ifdef PNG_READ_PACKSWAP_SUPPORTED
1523
if (png_ptr->transformations & PNG_PACKSWAP)
1524
png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
1525
#endif
1526
1527
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
1528
/* If gray -> RGB, do so now only if we did not do so above */
1529
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
1530
(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
1531
png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
1532
#endif
1533
1534
#ifdef PNG_READ_FILLER_SUPPORTED
1535
if (png_ptr->transformations & PNG_FILLER)
1536
png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
1537
(png_uint_32)png_ptr->filler, png_ptr->flags);
1538
#endif
1539
1540
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1541
if (png_ptr->transformations & PNG_INVERT_ALPHA)
1542
png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
1543
#endif
1544
1545
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1546
if (png_ptr->transformations & PNG_SWAP_ALPHA)
1547
png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
1548
#endif
1549
1550
#ifdef PNG_READ_SWAP_SUPPORTED
1551
if (png_ptr->transformations & PNG_SWAP_BYTES)
1552
png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
1553
#endif
1554
1555
#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
1556
if (png_ptr->transformations & PNG_USER_TRANSFORM)
1557
{
1558
if (png_ptr->read_user_transform_fn != NULL)
1559
(*(png_ptr->read_user_transform_fn)) /* User read transform function */
1560
(png_ptr, /* png_ptr */
1561
&(png_ptr->row_info), /* row_info: */
1562
/* png_uint_32 width; width of row */
1563
/* png_uint_32 rowbytes; number of bytes in row */
1564
/* png_byte color_type; color type of pixels */
1565
/* png_byte bit_depth; bit depth of samples */
1566
/* png_byte channels; number of channels (1-4) */
1567
/* png_byte pixel_depth; bits per pixel (depth*channels) */
1568
png_ptr->row_buf + 1); /* start of pixel data for row */
1569
#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
1570
if (png_ptr->user_transform_depth)
1571
png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
1572
if (png_ptr->user_transform_channels)
1573
png_ptr->row_info.channels = png_ptr->user_transform_channels;
1574
#endif
1575
png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
1576
png_ptr->row_info.channels);
1577
png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
1578
png_ptr->row_info.width);
1579
}
1580
#endif
1581
1582
}
1583
1584
#ifdef PNG_READ_PACK_SUPPORTED
1585
/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
1586
* without changing the actual values. Thus, if you had a row with
1587
* a bit depth of 1, you would end up with bytes that only contained
1588
* the numbers 0 or 1. If you would rather they contain 0 and 255, use
1589
* png_do_shift() after this.
1590
*/
1591
void /* PRIVATE */
1592
png_do_unpack(png_row_infop row_info, png_bytep row)
1593
{
1594
png_debug(1, "in png_do_unpack");
1595
1596
#ifdef PNG_USELESS_TESTS_SUPPORTED
1597
if (row != NULL && row_info != NULL && row_info->bit_depth < 8)
1598
#else
1599
if (row_info->bit_depth < 8)
1600
#endif
1601
{
1602
png_uint_32 i;
1603
png_uint_32 row_width=row_info->width;
1604
1605
switch (row_info->bit_depth)
1606
{
1607
case 1:
1608
{
1609
png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
1610
png_bytep dp = row + (png_size_t)row_width - 1;
1611
png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
1612
for (i = 0; i < row_width; i++)
1613
{
1614
*dp = (png_byte)((*sp >> shift) & 0x01);
1615
if (shift == 7)
1616
{
1617
shift = 0;
1618
sp--;
1619
}
1620
else
1621
shift++;
1622
1623
dp--;
1624
}
1625
break;
1626
}
1627
1628
case 2:
1629
{
1630
1631
png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
1632
png_bytep dp = row + (png_size_t)row_width - 1;
1633
png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
1634
for (i = 0; i < row_width; i++)
1635
{
1636
*dp = (png_byte)((*sp >> shift) & 0x03);
1637
if (shift == 6)
1638
{
1639
shift = 0;
1640
sp--;
1641
}
1642
else
1643
shift += 2;
1644
1645
dp--;
1646
}
1647
break;
1648
}
1649
1650
case 4:
1651
{
1652
png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
1653
png_bytep dp = row + (png_size_t)row_width - 1;
1654
png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
1655
for (i = 0; i < row_width; i++)
1656
{
1657
*dp = (png_byte)((*sp >> shift) & 0x0f);
1658
if (shift == 4)
1659
{
1660
shift = 0;
1661
sp--;
1662
}
1663
else
1664
shift = 4;
1665
1666
dp--;
1667
}
1668
break;
1669
}
1670
}
1671
row_info->bit_depth = 8;
1672
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
1673
row_info->rowbytes = row_width * row_info->channels;
1674
}
1675
}
1676
#endif
1677
1678
#ifdef PNG_READ_SHIFT_SUPPORTED
1679
/* Reverse the effects of png_do_shift. This routine merely shifts the
1680
* pixels back to their significant bits values. Thus, if you have
1681
* a row of bit depth 8, but only 5 are significant, this will shift
1682
* the values back to 0 through 31.
1683
*/
1684
void /* PRIVATE */
1685
png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
1686
{
1687
png_debug(1, "in png_do_unshift");
1688
1689
if (
1690
#ifdef PNG_USELESS_TESTS_SUPPORTED
1691
row != NULL && row_info != NULL && sig_bits != NULL &&
1692
#endif
1693
row_info->color_type != PNG_COLOR_TYPE_PALETTE)
1694
{
1695
int shift[4];
1696
int channels = 0;
1697
int c;
1698
png_uint_16 value = 0;
1699
png_uint_32 row_width = row_info->width;
1700
1701
if (row_info->color_type & PNG_COLOR_MASK_COLOR)
1702
{
1703
shift[channels++] = row_info->bit_depth - sig_bits->red;
1704
shift[channels++] = row_info->bit_depth - sig_bits->green;
1705
shift[channels++] = row_info->bit_depth - sig_bits->blue;
1706
}
1707
else
1708
{
1709
shift[channels++] = row_info->bit_depth - sig_bits->gray;
1710
}
1711
if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
1712
{
1713
shift[channels++] = row_info->bit_depth - sig_bits->alpha;
1714
}
1715
1716
for (c = 0; c < channels; c++)
1717
{
1718
if (shift[c] <= 0)
1719
shift[c] = 0;
1720
else
1721
value = 1;
1722
}
1723
1724
if (!value)
1725
return;
1726
1727
switch (row_info->bit_depth)
1728
{
1729
case 2:
1730
{
1731
png_bytep bp;
1732
png_uint_32 i;
1733
png_uint_32 istop = row_info->rowbytes;
1734
1735
for (bp = row, i = 0; i < istop; i++)
1736
{
1737
*bp >>= 1;
1738
*bp++ &= 0x55;
1739
}
1740
break;
1741
}
1742
1743
case 4:
1744
{
1745
png_bytep bp = row;
1746
png_uint_32 i;
1747
png_uint_32 istop = row_info->rowbytes;
1748
png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |
1749
(png_byte)((int)0xf >> shift[0]));
1750
1751
for (i = 0; i < istop; i++)
1752
{
1753
*bp >>= shift[0];
1754
*bp++ &= mask;
1755
}
1756
break;
1757
}
1758
1759
case 8:
1760
{
1761
png_bytep bp = row;
1762
png_uint_32 i;
1763
png_uint_32 istop = row_width * channels;
1764
1765
for (i = 0; i < istop; i++)
1766
{
1767
*bp++ >>= shift[i%channels];
1768
}
1769
break;
1770
}
1771
1772
case 16:
1773
{
1774
png_bytep bp = row;
1775
png_uint_32 i;
1776
png_uint_32 istop = channels * row_width;
1777
1778
for (i = 0; i < istop; i++)
1779
{
1780
value = (png_uint_16)((*bp << 8) + *(bp + 1));
1781
value >>= shift[i%channels];
1782
*bp++ = (png_byte)(value >> 8);
1783
*bp++ = (png_byte)(value & 0xff);
1784
}
1785
break;
1786
}
1787
}
1788
}
1789
}
1790
#endif
1791
1792
#ifdef PNG_READ_16_TO_8_SUPPORTED
1793
/* Chop rows of bit depth 16 down to 8 */
1794
void /* PRIVATE */
1795
png_do_chop(png_row_infop row_info, png_bytep row)
1796
{
1797
png_debug(1, "in png_do_chop");
1798
1799
#ifdef PNG_USELESS_TESTS_SUPPORTED
1800
if (row != NULL && row_info != NULL && row_info->bit_depth == 16)
1801
#else
1802
if (row_info->bit_depth == 16)
1803
#endif
1804
{
1805
png_bytep sp = row;
1806
png_bytep dp = row;
1807
png_uint_32 i;
1808
png_uint_32 istop = row_info->width * row_info->channels;
1809
1810
for (i = 0; i<istop; i++, sp += 2, dp++)
1811
{
1812
#ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
1813
/* This does a more accurate scaling of the 16-bit color
1814
* value, rather than a simple low-byte truncation.
1815
*
1816
* What the ideal calculation should be:
1817
* *dp = (((((png_uint_32)(*sp) << 8) |
1818
* (png_uint_32)(*(sp + 1))) * 255 + 127)
1819
* / (png_uint_32)65535L;
1820
*
1821
* GRR: no, I think this is what it really should be:
1822
* *dp = (((((png_uint_32)(*sp) << 8) |
1823
* (png_uint_32)(*(sp + 1))) + 128L)
1824
* / (png_uint_32)257L;
1825
*
1826
* GRR: here's the exact calculation with shifts:
1827
* temp = (((png_uint_32)(*sp) << 8) |
1828
* (png_uint_32)(*(sp + 1))) + 128L;
1829
* *dp = (temp - (temp >> 8)) >> 8;
1830
*
1831
* Approximate calculation with shift/add instead of multiply/divide:
1832
* *dp = ((((png_uint_32)(*sp) << 8) |
1833
* (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;
1834
*
1835
* What we actually do to avoid extra shifting and conversion:
1836
*/
1837
1838
*dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
1839
#else
1840
/* Simply discard the low order byte */
1841
*dp = *sp;
1842
#endif
1843
}
1844
row_info->bit_depth = 8;
1845
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
1846
row_info->rowbytes = row_info->width * row_info->channels;
1847
}
1848
}
1849
#endif
1850
1851
#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
1852
void /* PRIVATE */
1853
png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
1854
{
1855
png_debug(1, "in png_do_read_swap_alpha");
1856
1857
#ifdef PNG_USELESS_TESTS_SUPPORTED
1858
if (row != NULL && row_info != NULL)
1859
#endif
1860
{
1861
png_uint_32 row_width = row_info->width;
1862
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
1863
{
1864
/* This converts from RGBA to ARGB */
1865
if (row_info->bit_depth == 8)
1866
{
1867
png_bytep sp = row + row_info->rowbytes;
1868
png_bytep dp = sp;
1869
png_byte save;
1870
png_uint_32 i;
1871
1872
for (i = 0; i < row_width; i++)
1873
{
1874
save = *(--sp);
1875
*(--dp) = *(--sp);
1876
*(--dp) = *(--sp);
1877
*(--dp) = *(--sp);
1878
*(--dp) = save;
1879
}
1880
}
1881
/* This converts from RRGGBBAA to AARRGGBB */
1882
else
1883
{
1884
png_bytep sp = row + row_info->rowbytes;
1885
png_bytep dp = sp;
1886
png_byte save[2];
1887
png_uint_32 i;
1888
1889
for (i = 0; i < row_width; i++)
1890
{
1891
save[0] = *(--sp);
1892
save[1] = *(--sp);
1893
*(--dp) = *(--sp);
1894
*(--dp) = *(--sp);
1895
*(--dp) = *(--sp);
1896
*(--dp) = *(--sp);
1897
*(--dp) = *(--sp);
1898
*(--dp) = *(--sp);
1899
*(--dp) = save[0];
1900
*(--dp) = save[1];
1901
}
1902
}
1903
}
1904
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
1905
{
1906
/* This converts from GA to AG */
1907
if (row_info->bit_depth == 8)
1908
{
1909
png_bytep sp = row + row_info->rowbytes;
1910
png_bytep dp = sp;
1911
png_byte save;
1912
png_uint_32 i;
1913
1914
for (i = 0; i < row_width; i++)
1915
{
1916
save = *(--sp);
1917
*(--dp) = *(--sp);
1918
*(--dp) = save;
1919
}
1920
}
1921
/* This converts from GGAA to AAGG */
1922
else
1923
{
1924
png_bytep sp = row + row_info->rowbytes;
1925
png_bytep dp = sp;
1926
png_byte save[2];
1927
png_uint_32 i;
1928
1929
for (i = 0; i < row_width; i++)
1930
{
1931
save[0] = *(--sp);
1932
save[1] = *(--sp);
1933
*(--dp) = *(--sp);
1934
*(--dp) = *(--sp);
1935
*(--dp) = save[0];
1936
*(--dp) = save[1];
1937
}
1938
}
1939
}
1940
}
1941
}
1942
#endif
1943
1944
#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
1945
void /* PRIVATE */
1946
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
1947
{
1948
png_debug(1, "in png_do_read_invert_alpha");
1949
1950
#ifdef PNG_USELESS_TESTS_SUPPORTED
1951
if (row != NULL && row_info != NULL)
1952
#endif
1953
{
1954
png_uint_32 row_width = row_info->width;
1955
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
1956
{
1957
/* This inverts the alpha channel in RGBA */
1958
if (row_info->bit_depth == 8)
1959
{
1960
png_bytep sp = row + row_info->rowbytes;
1961
png_bytep dp = sp;
1962
png_uint_32 i;
1963
1964
for (i = 0; i < row_width; i++)
1965
{
1966
*(--dp) = (png_byte)(255 - *(--sp));
1967
1968
/* This does nothing:
1969
*(--dp) = *(--sp);
1970
*(--dp) = *(--sp);
1971
*(--dp) = *(--sp);
1972
We can replace it with:
1973
*/
1974
sp-=3;
1975
dp=sp;
1976
}
1977
}
1978
/* This inverts the alpha channel in RRGGBBAA */
1979
else
1980
{
1981
png_bytep sp = row + row_info->rowbytes;
1982
png_bytep dp = sp;
1983
png_uint_32 i;
1984
1985
for (i = 0; i < row_width; i++)
1986
{
1987
*(--dp) = (png_byte)(255 - *(--sp));
1988
*(--dp) = (png_byte)(255 - *(--sp));
1989
1990
/* This does nothing:
1991
*(--dp) = *(--sp);
1992
*(--dp) = *(--sp);
1993
*(--dp) = *(--sp);
1994
*(--dp) = *(--sp);
1995
*(--dp) = *(--sp);
1996
*(--dp) = *(--sp);
1997
We can replace it with:
1998
*/
1999
sp-=6;
2000
dp=sp;
2001
}
2002
}
2003
}
2004
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
2005
{
2006
/* This inverts the alpha channel in GA */
2007
if (row_info->bit_depth == 8)
2008
{
2009
png_bytep sp = row + row_info->rowbytes;
2010
png_bytep dp = sp;
2011
png_uint_32 i;
2012
2013
for (i = 0; i < row_width; i++)
2014
{
2015
*(--dp) = (png_byte)(255 - *(--sp));
2016
*(--dp) = *(--sp);
2017
}
2018
}
2019
/* This inverts the alpha channel in GGAA */
2020
else
2021
{
2022
png_bytep sp = row + row_info->rowbytes;
2023
png_bytep dp = sp;
2024
png_uint_32 i;
2025
2026
for (i = 0; i < row_width; i++)
2027
{
2028
*(--dp) = (png_byte)(255 - *(--sp));
2029
*(--dp) = (png_byte)(255 - *(--sp));
2030
/*
2031
*(--dp) = *(--sp);
2032
*(--dp) = *(--sp);
2033
*/
2034
sp-=2;
2035
dp=sp;
2036
}
2037
}
2038
}
2039
}
2040
}
2041
#endif
2042
2043
#ifdef PNG_READ_FILLER_SUPPORTED
2044
/* Add filler channel if we have RGB color */
2045
void /* PRIVATE */
2046
png_do_read_filler(png_row_infop row_info, png_bytep row,
2047
png_uint_32 filler, png_uint_32 flags)
2048
{
2049
png_uint_32 i;
2050
png_uint_32 row_width = row_info->width;
2051
2052
png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
2053
png_byte lo_filler = (png_byte)(filler & 0xff);
2054
2055
png_debug(1, "in png_do_read_filler");
2056
2057
if (
2058
#ifdef PNG_USELESS_TESTS_SUPPORTED
2059
row != NULL && row_info != NULL &&
2060
#endif
2061
row_info->color_type == PNG_COLOR_TYPE_GRAY)
2062
{
2063
if (row_info->bit_depth == 8)
2064
{
2065
/* This changes the data from G to GX */
2066
if (flags & PNG_FLAG_FILLER_AFTER)
2067
{
2068
png_bytep sp = row + (png_size_t)row_width;
2069
png_bytep dp = sp + (png_size_t)row_width;
2070
for (i = 1; i < row_width; i++)
2071
{
2072
*(--dp) = lo_filler;
2073
*(--dp) = *(--sp);
2074
}
2075
*(--dp) = lo_filler;
2076
row_info->channels = 2;
2077
row_info->pixel_depth = 16;
2078
row_info->rowbytes = row_width * 2;
2079
}
2080
/* This changes the data from G to XG */
2081
else
2082
{
2083
png_bytep sp = row + (png_size_t)row_width;
2084
png_bytep dp = sp + (png_size_t)row_width;
2085
for (i = 0; i < row_width; i++)
2086
{
2087
*(--dp) = *(--sp);
2088
*(--dp) = lo_filler;
2089
}
2090
row_info->channels = 2;
2091
row_info->pixel_depth = 16;
2092
row_info->rowbytes = row_width * 2;
2093
}
2094
}
2095
else if (row_info->bit_depth == 16)
2096
{
2097
/* This changes the data from GG to GGXX */
2098
if (flags & PNG_FLAG_FILLER_AFTER)
2099
{
2100
png_bytep sp = row + (png_size_t)row_width * 2;
2101
png_bytep dp = sp + (png_size_t)row_width * 2;
2102
for (i = 1; i < row_width; i++)
2103
{
2104
*(--dp) = hi_filler;
2105
*(--dp) = lo_filler;
2106
*(--dp) = *(--sp);
2107
*(--dp) = *(--sp);
2108
}
2109
*(--dp) = hi_filler;
2110
*(--dp) = lo_filler;
2111
row_info->channels = 2;
2112
row_info->pixel_depth = 32;
2113
row_info->rowbytes = row_width * 4;
2114
}
2115
/* This changes the data from GG to XXGG */
2116
else
2117
{
2118
png_bytep sp = row + (png_size_t)row_width * 2;
2119
png_bytep dp = sp + (png_size_t)row_width * 2;
2120
for (i = 0; i < row_width; i++)
2121
{
2122
*(--dp) = *(--sp);
2123
*(--dp) = *(--sp);
2124
*(--dp) = hi_filler;
2125
*(--dp) = lo_filler;
2126
}
2127
row_info->channels = 2;
2128
row_info->pixel_depth = 32;
2129
row_info->rowbytes = row_width * 4;
2130
}
2131
}
2132
} /* COLOR_TYPE == GRAY */
2133
else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
2134
{
2135
if (row_info->bit_depth == 8)
2136
{
2137
/* This changes the data from RGB to RGBX */
2138
if (flags & PNG_FLAG_FILLER_AFTER)
2139
{
2140
png_bytep sp = row + (png_size_t)row_width * 3;
2141
png_bytep dp = sp + (png_size_t)row_width;
2142
for (i = 1; i < row_width; i++)
2143
{
2144
*(--dp) = lo_filler;
2145
*(--dp) = *(--sp);
2146
*(--dp) = *(--sp);
2147
*(--dp) = *(--sp);
2148
}
2149
*(--dp) = lo_filler;
2150
row_info->channels = 4;
2151
row_info->pixel_depth = 32;
2152
row_info->rowbytes = row_width * 4;
2153
}
2154
/* This changes the data from RGB to XRGB */
2155
else
2156
{
2157
png_bytep sp = row + (png_size_t)row_width * 3;
2158
png_bytep dp = sp + (png_size_t)row_width;
2159
for (i = 0; i < row_width; i++)
2160
{
2161
*(--dp) = *(--sp);
2162
*(--dp) = *(--sp);
2163
*(--dp) = *(--sp);
2164
*(--dp) = lo_filler;
2165
}
2166
row_info->channels = 4;
2167
row_info->pixel_depth = 32;
2168
row_info->rowbytes = row_width * 4;
2169
}
2170
}
2171
else if (row_info->bit_depth == 16)
2172
{
2173
/* This changes the data from RRGGBB to RRGGBBXX */
2174
if (flags & PNG_FLAG_FILLER_AFTER)
2175
{
2176
png_bytep sp = row + (png_size_t)row_width * 6;
2177
png_bytep dp = sp + (png_size_t)row_width * 2;
2178
for (i = 1; i < row_width; i++)
2179
{
2180
*(--dp) = hi_filler;
2181
*(--dp) = lo_filler;
2182
*(--dp) = *(--sp);
2183
*(--dp) = *(--sp);
2184
*(--dp) = *(--sp);
2185
*(--dp) = *(--sp);
2186
*(--dp) = *(--sp);
2187
*(--dp) = *(--sp);
2188
}
2189
*(--dp) = hi_filler;
2190
*(--dp) = lo_filler;
2191
row_info->channels = 4;
2192
row_info->pixel_depth = 64;
2193
row_info->rowbytes = row_width * 8;
2194
}
2195
/* This changes the data from RRGGBB to XXRRGGBB */
2196
else
2197
{
2198
png_bytep sp = row + (png_size_t)row_width * 6;
2199
png_bytep dp = sp + (png_size_t)row_width * 2;
2200
for (i = 0; i < row_width; i++)
2201
{
2202
*(--dp) = *(--sp);
2203
*(--dp) = *(--sp);
2204
*(--dp) = *(--sp);
2205
*(--dp) = *(--sp);
2206
*(--dp) = *(--sp);
2207
*(--dp) = *(--sp);
2208
*(--dp) = hi_filler;
2209
*(--dp) = lo_filler;
2210
}
2211
row_info->channels = 4;
2212
row_info->pixel_depth = 64;
2213
row_info->rowbytes = row_width * 8;
2214
}
2215
}
2216
} /* COLOR_TYPE == RGB */
2217
}
2218
#endif
2219
2220
#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
2221
/* Expand grayscale files to RGB, with or without alpha */
2222
void /* PRIVATE */
2223
png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
2224
{
2225
png_uint_32 i;
2226
png_uint_32 row_width = row_info->width;
2227
2228
png_debug(1, "in png_do_gray_to_rgb");
2229
2230
if (row_info->bit_depth >= 8 &&
2231
#ifdef PNG_USELESS_TESTS_SUPPORTED
2232
row != NULL && row_info != NULL &&
2233
#endif
2234
!(row_info->color_type & PNG_COLOR_MASK_COLOR))
2235
{
2236
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
2237
{
2238
if (row_info->bit_depth == 8)
2239
{
2240
png_bytep sp = row + (png_size_t)row_width - 1;
2241
png_bytep dp = sp + (png_size_t)row_width * 2;
2242
for (i = 0; i < row_width; i++)
2243
{
2244
*(dp--) = *sp;
2245
*(dp--) = *sp;
2246
*(dp--) = *(sp--);
2247
}
2248
}
2249
else
2250
{
2251
png_bytep sp = row + (png_size_t)row_width * 2 - 1;
2252
png_bytep dp = sp + (png_size_t)row_width * 4;
2253
for (i = 0; i < row_width; i++)
2254
{
2255
*(dp--) = *sp;
2256
*(dp--) = *(sp - 1);
2257
*(dp--) = *sp;
2258
*(dp--) = *(sp - 1);
2259
*(dp--) = *(sp--);
2260
*(dp--) = *(sp--);
2261
}
2262
}
2263
}
2264
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
2265
{
2266
if (row_info->bit_depth == 8)
2267
{
2268
png_bytep sp = row + (png_size_t)row_width * 2 - 1;
2269
png_bytep dp = sp + (png_size_t)row_width * 2;
2270
for (i = 0; i < row_width; i++)
2271
{
2272
*(dp--) = *(sp--);
2273
*(dp--) = *sp;
2274
*(dp--) = *sp;
2275
*(dp--) = *(sp--);
2276
}
2277
}
2278
else
2279
{
2280
png_bytep sp = row + (png_size_t)row_width * 4 - 1;
2281
png_bytep dp = sp + (png_size_t)row_width * 4;
2282
for (i = 0; i < row_width; i++)
2283
{
2284
*(dp--) = *(sp--);
2285
*(dp--) = *(sp--);
2286
*(dp--) = *sp;
2287
*(dp--) = *(sp - 1);
2288
*(dp--) = *sp;
2289
*(dp--) = *(sp - 1);
2290
*(dp--) = *(sp--);
2291
*(dp--) = *(sp--);
2292
}
2293
}
2294
}
2295
row_info->channels += (png_byte)2;
2296
row_info->color_type |= PNG_COLOR_MASK_COLOR;
2297
row_info->pixel_depth = (png_byte)(row_info->channels *
2298
row_info->bit_depth);
2299
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
2300
}
2301
}
2302
#endif
2303
2304
#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
2305
/* Reduce RGB files to grayscale, with or without alpha
2306
* using the equation given in Poynton's ColorFAQ at
2307
* <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)
2308
* New link:
2309
* <http://www.poynton.com/notes/colour_and_gamma/>
2310
* Charles Poynton poynton at poynton.com
2311
*
2312
* Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
2313
*
2314
* We approximate this with
2315
*
2316
* Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
2317
*
2318
* which can be expressed with integers as
2319
*
2320
* Y = (6969 * R + 23434 * G + 2365 * B)/32768
2321
*
2322
* The calculation is to be done in a linear colorspace.
2323
*
2324
* Other integer coefficents can be used via png_set_rgb_to_gray().
2325
*/
2326
int /* PRIVATE */
2327
png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
2328
2329
{
2330
png_uint_32 i;
2331
2332
png_uint_32 row_width = row_info->width;
2333
int rgb_error = 0;
2334
2335
png_debug(1, "in png_do_rgb_to_gray");
2336
2337
if (
2338
#ifdef PNG_USELESS_TESTS_SUPPORTED
2339
row != NULL && row_info != NULL &&
2340
#endif
2341
(row_info->color_type & PNG_COLOR_MASK_COLOR))
2342
{
2343
png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
2344
png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
2345
png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
2346
2347
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
2348
{
2349
if (row_info->bit_depth == 8)
2350
{
2351
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
2352
if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
2353
{
2354
png_bytep sp = row;
2355
png_bytep dp = row;
2356
2357
for (i = 0; i < row_width; i++)
2358
{
2359
png_byte red = png_ptr->gamma_to_1[*(sp++)];
2360
png_byte green = png_ptr->gamma_to_1[*(sp++)];
2361
png_byte blue = png_ptr->gamma_to_1[*(sp++)];
2362
if (red != green || red != blue)
2363
{
2364
rgb_error |= 1;
2365
*(dp++) = png_ptr->gamma_from_1[
2366
(rc*red + gc*green + bc*blue)>>15];
2367
}
2368
else
2369
*(dp++) = *(sp - 1);
2370
}
2371
}
2372
else
2373
#endif
2374
{
2375
png_bytep sp = row;
2376
png_bytep dp = row;
2377
for (i = 0; i < row_width; i++)
2378
{
2379
png_byte red = *(sp++);
2380
png_byte green = *(sp++);
2381
png_byte blue = *(sp++);
2382
if (red != green || red != blue)
2383
{
2384
rgb_error |= 1;
2385
*(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
2386
}
2387
else
2388
*(dp++) = *(sp - 1);
2389
}
2390
}
2391
}
2392
2393
else /* RGB bit_depth == 16 */
2394
{
2395
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
2396
if (png_ptr->gamma_16_to_1 != NULL &&
2397
png_ptr->gamma_16_from_1 != NULL)
2398
{
2399
png_bytep sp = row;
2400
png_bytep dp = row;
2401
for (i = 0; i < row_width; i++)
2402
{
2403
png_uint_16 red, green, blue, w;
2404
2405
red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2406
green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2407
blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2408
2409
if (red == green && red == blue)
2410
w = red;
2411
else
2412
{
2413
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
2414
png_ptr->gamma_shift][red>>8];
2415
png_uint_16 green_1 =
2416
png_ptr->gamma_16_to_1[(green&0xff) >>
2417
png_ptr->gamma_shift][green>>8];
2418
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
2419
png_ptr->gamma_shift][blue>>8];
2420
png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
2421
+ bc*blue_1)>>15);
2422
w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
2423
png_ptr->gamma_shift][gray16 >> 8];
2424
rgb_error |= 1;
2425
}
2426
2427
*(dp++) = (png_byte)((w>>8) & 0xff);
2428
*(dp++) = (png_byte)(w & 0xff);
2429
}
2430
}
2431
else
2432
#endif
2433
{
2434
png_bytep sp = row;
2435
png_bytep dp = row;
2436
for (i = 0; i < row_width; i++)
2437
{
2438
png_uint_16 red, green, blue, gray16;
2439
2440
red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2441
green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2442
blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2443
2444
if (red != green || red != blue)
2445
rgb_error |= 1;
2446
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
2447
*(dp++) = (png_byte)((gray16>>8) & 0xff);
2448
*(dp++) = (png_byte)(gray16 & 0xff);
2449
}
2450
}
2451
}
2452
}
2453
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
2454
{
2455
if (row_info->bit_depth == 8)
2456
{
2457
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
2458
if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
2459
{
2460
png_bytep sp = row;
2461
png_bytep dp = row;
2462
for (i = 0; i < row_width; i++)
2463
{
2464
png_byte red = png_ptr->gamma_to_1[*(sp++)];
2465
png_byte green = png_ptr->gamma_to_1[*(sp++)];
2466
png_byte blue = png_ptr->gamma_to_1[*(sp++)];
2467
if (red != green || red != blue)
2468
rgb_error |= 1;
2469
*(dp++) = png_ptr->gamma_from_1
2470
[(rc*red + gc*green + bc*blue)>>15];
2471
*(dp++) = *(sp++); /* alpha */
2472
}
2473
}
2474
else
2475
#endif
2476
{
2477
png_bytep sp = row;
2478
png_bytep dp = row;
2479
for (i = 0; i < row_width; i++)
2480
{
2481
png_byte red = *(sp++);
2482
png_byte green = *(sp++);
2483
png_byte blue = *(sp++);
2484
if (red != green || red != blue)
2485
rgb_error |= 1;
2486
*(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
2487
*(dp++) = *(sp++); /* alpha */
2488
}
2489
}
2490
}
2491
else /* RGBA bit_depth == 16 */
2492
{
2493
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
2494
if (png_ptr->gamma_16_to_1 != NULL &&
2495
png_ptr->gamma_16_from_1 != NULL)
2496
{
2497
png_bytep sp = row;
2498
png_bytep dp = row;
2499
for (i = 0; i < row_width; i++)
2500
{
2501
png_uint_16 red, green, blue, w;
2502
2503
red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2504
green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2505
blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
2506
2507
if (red == green && red == blue)
2508
w = red;
2509
else
2510
{
2511
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
2512
png_ptr->gamma_shift][red>>8];
2513
png_uint_16 green_1 =
2514
png_ptr->gamma_16_to_1[(green&0xff) >>
2515
png_ptr->gamma_shift][green>>8];
2516
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
2517
png_ptr->gamma_shift][blue>>8];
2518
png_uint_16 gray16 = (png_uint_16)((rc * red_1
2519
+ gc * green_1 + bc * blue_1)>>15);
2520
w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
2521
png_ptr->gamma_shift][gray16 >> 8];
2522
rgb_error |= 1;
2523
}
2524
2525
*(dp++) = (png_byte)((w>>8) & 0xff);
2526
*(dp++) = (png_byte)(w & 0xff);
2527
*(dp++) = *(sp++); /* alpha */
2528
*(dp++) = *(sp++);
2529
}
2530
}
2531
else
2532
#endif
2533
{
2534
png_bytep sp = row;
2535
png_bytep dp = row;
2536
for (i = 0; i < row_width; i++)
2537
{
2538
png_uint_16 red, green, blue, gray16;
2539
red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
2540
green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
2541
blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
2542
if (red != green || red != blue)
2543
rgb_error |= 1;
2544
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
2545
*(dp++) = (png_byte)((gray16>>8) & 0xff);
2546
*(dp++) = (png_byte)(gray16 & 0xff);
2547
*(dp++) = *(sp++); /* alpha */
2548
*(dp++) = *(sp++);
2549
}
2550
}
2551
}
2552
}
2553
row_info->channels -= (png_byte)2;
2554
row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
2555
row_info->pixel_depth = (png_byte)(row_info->channels *
2556
row_info->bit_depth);
2557
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
2558
}
2559
return rgb_error;
2560
}
2561
#endif
2562
2563
/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
2564
* large of png_color. This lets grayscale images be treated as
2565
* paletted. Most useful for gamma correction and simplification
2566
* of code.
2567
*/
2568
void PNGAPI
2569
png_build_grayscale_palette(int bit_depth, png_colorp palette)
2570
{
2571
int num_palette;
2572
int color_inc;
2573
int i;
2574
int v;
2575
2576
png_debug(1, "in png_do_build_grayscale_palette");
2577
2578
if (palette == NULL)
2579
return;
2580
2581
switch (bit_depth)
2582
{
2583
case 1:
2584
num_palette = 2;
2585
color_inc = 0xff;
2586
break;
2587
2588
case 2:
2589
num_palette = 4;
2590
color_inc = 0x55;
2591
break;
2592
2593
case 4:
2594
num_palette = 16;
2595
color_inc = 0x11;
2596
break;
2597
2598
case 8:
2599
num_palette = 256;
2600
color_inc = 1;
2601
break;
2602
2603
default:
2604
num_palette = 0;
2605
color_inc = 0;
2606
break;
2607
}
2608
2609
for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
2610
{
2611
palette[i].red = (png_byte)v;
2612
palette[i].green = (png_byte)v;
2613
palette[i].blue = (png_byte)v;
2614
}
2615
}
2616
2617
/* This function is currently unused. Do we really need it? */
2618
#if defined(PNG_READ_DITHER_SUPPORTED) && \
2619
defined(PNG_CORRECT_PALETTE_SUPPORTED)
2620
void /* PRIVATE */
2621
png_correct_palette(png_structp png_ptr, png_colorp palette,
2622
int num_palette)
2623
{
2624
png_debug(1, "in png_correct_palette");
2625
2626
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
2627
defined(PNG_READ_GAMMA_SUPPORTED) && \
2628
defined(PNG_FLOATING_POINT_SUPPORTED)
2629
if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
2630
{
2631
png_color back, back_1;
2632
2633
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
2634
{
2635
back.red = png_ptr->gamma_table[png_ptr->background.red];
2636
back.green = png_ptr->gamma_table[png_ptr->background.green];
2637
back.blue = png_ptr->gamma_table[png_ptr->background.blue];
2638
2639
back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
2640
back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
2641
back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
2642
}
2643
else
2644
{
2645
double g;
2646
2647
g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
2648
2649
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN
2650
|| fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
2651
{
2652
back.red = png_ptr->background.red;
2653
back.green = png_ptr->background.green;
2654
back.blue = png_ptr->background.blue;
2655
}
2656
else
2657
{
2658
back.red =
2659
(png_byte)(pow((double)png_ptr->background.red/255, g) *
2660
255.0 + 0.5);
2661
back.green =
2662
(png_byte)(pow((double)png_ptr->background.green/255, g) *
2663
255.0 + 0.5);
2664
back.blue =
2665
(png_byte)(pow((double)png_ptr->background.blue/255, g) *
2666
255.0 + 0.5);
2667
}
2668
2669
g = 1.0 / png_ptr->background_gamma;
2670
2671
back_1.red =
2672
(png_byte)(pow((double)png_ptr->background.red/255, g) *
2673
255.0 + 0.5);
2674
back_1.green =
2675
(png_byte)(pow((double)png_ptr->background.green/255, g) *
2676
255.0 + 0.5);
2677
back_1.blue =
2678
(png_byte)(pow((double)png_ptr->background.blue/255, g) *
2679
255.0 + 0.5);
2680
}
2681
2682
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
2683
{
2684
png_uint_32 i;
2685
2686
for (i = 0; i < (png_uint_32)num_palette; i++)
2687
{
2688
if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)
2689
{
2690
palette[i] = back;
2691
}
2692
else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)
2693
{
2694
png_byte v, w;
2695
2696
v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
2697
png_composite(w, v, png_ptr->trans[i], back_1.red);
2698
palette[i].red = png_ptr->gamma_from_1[w];
2699
2700
v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
2701
png_composite(w, v, png_ptr->trans[i], back_1.green);
2702
palette[i].green = png_ptr->gamma_from_1[w];
2703
2704
v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
2705
png_composite(w, v, png_ptr->trans[i], back_1.blue);
2706
palette[i].blue = png_ptr->gamma_from_1[w];
2707
}
2708
else
2709
{
2710
palette[i].red = png_ptr->gamma_table[palette[i].red];
2711
palette[i].green = png_ptr->gamma_table[palette[i].green];
2712
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
2713
}
2714
}
2715
}
2716
else
2717
{
2718
int i;
2719
2720
for (i = 0; i < num_palette; i++)
2721
{
2722
if (palette[i].red == (png_byte)png_ptr->trans_values.gray)
2723
{
2724
palette[i] = back;
2725
}
2726
else
2727
{
2728
palette[i].red = png_ptr->gamma_table[palette[i].red];
2729
palette[i].green = png_ptr->gamma_table[palette[i].green];
2730
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
2731
}
2732
}
2733
}
2734
}
2735
else
2736
#endif
2737
#ifdef PNG_READ_GAMMA_SUPPORTED
2738
if (png_ptr->transformations & PNG_GAMMA)
2739
{
2740
int i;
2741
2742
for (i = 0; i < num_palette; i++)
2743
{
2744
palette[i].red = png_ptr->gamma_table[palette[i].red];
2745
palette[i].green = png_ptr->gamma_table[palette[i].green];
2746
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
2747
}
2748
}
2749
#ifdef PNG_READ_BACKGROUND_SUPPORTED
2750
else
2751
#endif
2752
#endif
2753
#ifdef PNG_READ_BACKGROUND_SUPPORTED
2754
if (png_ptr->transformations & PNG_BACKGROUND)
2755
{
2756
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
2757
{
2758
png_color back;
2759
2760
back.red = (png_byte)png_ptr->background.red;
2761
back.green = (png_byte)png_ptr->background.green;
2762
back.blue = (png_byte)png_ptr->background.blue;
2763
2764
for (i = 0; i < (int)png_ptr->num_trans; i++)
2765
{
2766
if (png_ptr->trans[i] == 0)
2767
{
2768
palette[i].red = back.red;
2769
palette[i].green = back.green;
2770
palette[i].blue = back.blue;
2771
}
2772
else if (png_ptr->trans[i] != 0xff)
2773
{
2774
png_composite(palette[i].red, png_ptr->palette[i].red,
2775
png_ptr->trans[i], back.red);
2776
png_composite(palette[i].green, png_ptr->palette[i].green,
2777
png_ptr->trans[i], back.green);
2778
png_composite(palette[i].blue, png_ptr->palette[i].blue,
2779
png_ptr->trans[i], back.blue);
2780
}
2781
}
2782
}
2783
else /* Assume grayscale palette (what else could it be?) */
2784
{
2785
int i;
2786
2787
for (i = 0; i < num_palette; i++)
2788
{
2789
if (i == (png_byte)png_ptr->trans_values.gray)
2790
{
2791
palette[i].red = (png_byte)png_ptr->background.red;
2792
palette[i].green = (png_byte)png_ptr->background.green;
2793
palette[i].blue = (png_byte)png_ptr->background.blue;
2794
}
2795
}
2796
}
2797
}
2798
#endif
2799
}
2800
#endif
2801
2802
#ifdef PNG_READ_BACKGROUND_SUPPORTED
2803
/* Replace any alpha or transparency with the supplied background color.
2804
* "background" is already in the screen gamma, while "background_1" is
2805
* at a gamma of 1.0. Paletted files have already been taken care of.
2806
*/
2807
void /* PRIVATE */
2808
png_do_background(png_row_infop row_info, png_bytep row,
2809
png_color_16p trans_values, png_color_16p background
2810
#ifdef PNG_READ_GAMMA_SUPPORTED
2811
, png_color_16p background_1,
2812
png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
2813
png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
2814
png_uint_16pp gamma_16_to_1, int gamma_shift
2815
#endif
2816
)
2817
{
2818
png_bytep sp, dp;
2819
png_uint_32 i;
2820
png_uint_32 row_width=row_info->width;
2821
int shift;
2822
2823
png_debug(1, "in png_do_background");
2824
2825
if (background != NULL &&
2826
#ifdef PNG_USELESS_TESTS_SUPPORTED
2827
row != NULL && row_info != NULL &&
2828
#endif
2829
(!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
2830
(row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values)))
2831
{
2832
switch (row_info->color_type)
2833
{
2834
case PNG_COLOR_TYPE_GRAY:
2835
{
2836
switch (row_info->bit_depth)
2837
{
2838
case 1:
2839
{
2840
sp = row;
2841
shift = 7;
2842
for (i = 0; i < row_width; i++)
2843
{
2844
if ((png_uint_16)((*sp >> shift) & 0x01)
2845
== trans_values->gray)
2846
{
2847
*sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
2848
*sp |= (png_byte)(background->gray << shift);
2849
}
2850
if (!shift)
2851
{
2852
shift = 7;
2853
sp++;
2854
}
2855
else
2856
shift--;
2857
}
2858
break;
2859
}
2860
2861
case 2:
2862
{
2863
#ifdef PNG_READ_GAMMA_SUPPORTED
2864
if (gamma_table != NULL)
2865
{
2866
sp = row;
2867
shift = 6;
2868
for (i = 0; i < row_width; i++)
2869
{
2870
if ((png_uint_16)((*sp >> shift) & 0x03)
2871
== trans_values->gray)
2872
{
2873
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
2874
*sp |= (png_byte)(background->gray << shift);
2875
}
2876
else
2877
{
2878
png_byte p = (png_byte)((*sp >> shift) & 0x03);
2879
png_byte g = (png_byte)((gamma_table [p | (p << 2) |
2880
(p << 4) | (p << 6)] >> 6) & 0x03);
2881
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
2882
*sp |= (png_byte)(g << shift);
2883
}
2884
if (!shift)
2885
{
2886
shift = 6;
2887
sp++;
2888
}
2889
else
2890
shift -= 2;
2891
}
2892
}
2893
else
2894
#endif
2895
{
2896
sp = row;
2897
shift = 6;
2898
for (i = 0; i < row_width; i++)
2899
{
2900
if ((png_uint_16)((*sp >> shift) & 0x03)
2901
== trans_values->gray)
2902
{
2903
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
2904
*sp |= (png_byte)(background->gray << shift);
2905
}
2906
if (!shift)
2907
{
2908
shift = 6;
2909
sp++;
2910
}
2911
else
2912
shift -= 2;
2913
}
2914
}
2915
break;
2916
}
2917
2918
case 4:
2919
{
2920
#ifdef PNG_READ_GAMMA_SUPPORTED
2921
if (gamma_table != NULL)
2922
{
2923
sp = row;
2924
shift = 4;
2925
for (i = 0; i < row_width; i++)
2926
{
2927
if ((png_uint_16)((*sp >> shift) & 0x0f)
2928
== trans_values->gray)
2929
{
2930
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
2931
*sp |= (png_byte)(background->gray << shift);
2932
}
2933
else
2934
{
2935
png_byte p = (png_byte)((*sp >> shift) & 0x0f);
2936
png_byte g = (png_byte)((gamma_table[p |
2937
(p << 4)] >> 4) & 0x0f);
2938
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
2939
*sp |= (png_byte)(g << shift);
2940
}
2941
if (!shift)
2942
{
2943
shift = 4;
2944
sp++;
2945
}
2946
else
2947
shift -= 4;
2948
}
2949
}
2950
else
2951
#endif
2952
{
2953
sp = row;
2954
shift = 4;
2955
for (i = 0; i < row_width; i++)
2956
{
2957
if ((png_uint_16)((*sp >> shift) & 0x0f)
2958
== trans_values->gray)
2959
{
2960
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
2961
*sp |= (png_byte)(background->gray << shift);
2962
}
2963
if (!shift)
2964
{
2965
shift = 4;
2966
sp++;
2967
}
2968
else
2969
shift -= 4;
2970
}
2971
}
2972
break;
2973
}
2974
2975
case 8:
2976
{
2977
#ifdef PNG_READ_GAMMA_SUPPORTED
2978
if (gamma_table != NULL)
2979
{
2980
sp = row;
2981
for (i = 0; i < row_width; i++, sp++)
2982
{
2983
if (*sp == trans_values->gray)
2984
{
2985
*sp = (png_byte)background->gray;
2986
}
2987
else
2988
{
2989
*sp = gamma_table[*sp];
2990
}
2991
}
2992
}
2993
else
2994
#endif
2995
{
2996
sp = row;
2997
for (i = 0; i < row_width; i++, sp++)
2998
{
2999
if (*sp == trans_values->gray)
3000
{
3001
*sp = (png_byte)background->gray;
3002
}
3003
}
3004
}
3005
break;
3006
}
3007
3008
case 16:
3009
{
3010
#ifdef PNG_READ_GAMMA_SUPPORTED
3011
if (gamma_16 != NULL)
3012
{
3013
sp = row;
3014
for (i = 0; i < row_width; i++, sp += 2)
3015
{
3016
png_uint_16 v;
3017
3018
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
3019
if (v == trans_values->gray)
3020
{
3021
/* Background is already in screen gamma */
3022
*sp = (png_byte)((background->gray >> 8) & 0xff);
3023
*(sp + 1) = (png_byte)(background->gray & 0xff);
3024
}
3025
else
3026
{
3027
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
3028
*sp = (png_byte)((v >> 8) & 0xff);
3029
*(sp + 1) = (png_byte)(v & 0xff);
3030
}
3031
}
3032
}
3033
else
3034
#endif
3035
{
3036
sp = row;
3037
for (i = 0; i < row_width; i++, sp += 2)
3038
{
3039
png_uint_16 v;
3040
3041
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
3042
if (v == trans_values->gray)
3043
{
3044
*sp = (png_byte)((background->gray >> 8) & 0xff);
3045
*(sp + 1) = (png_byte)(background->gray & 0xff);
3046
}
3047
}
3048
}
3049
break;
3050
}
3051
}
3052
break;
3053
}
3054
3055
case PNG_COLOR_TYPE_RGB:
3056
{
3057
if (row_info->bit_depth == 8)
3058
{
3059
#ifdef PNG_READ_GAMMA_SUPPORTED
3060
if (gamma_table != NULL)
3061
{
3062
sp = row;
3063
for (i = 0; i < row_width; i++, sp += 3)
3064
{
3065
if (*sp == trans_values->red &&
3066
*(sp + 1) == trans_values->green &&
3067
*(sp + 2) == trans_values->blue)
3068
{
3069
*sp = (png_byte)background->red;
3070
*(sp + 1) = (png_byte)background->green;
3071
*(sp + 2) = (png_byte)background->blue;
3072
}
3073
else
3074
{
3075
*sp = gamma_table[*sp];
3076
*(sp + 1) = gamma_table[*(sp + 1)];
3077
*(sp + 2) = gamma_table[*(sp + 2)];
3078
}
3079
}
3080
}
3081
else
3082
#endif
3083
{
3084
sp = row;
3085
for (i = 0; i < row_width; i++, sp += 3)
3086
{
3087
if (*sp == trans_values->red &&
3088
*(sp + 1) == trans_values->green &&
3089
*(sp + 2) == trans_values->blue)
3090
{
3091
*sp = (png_byte)background->red;
3092
*(sp + 1) = (png_byte)background->green;
3093
*(sp + 2) = (png_byte)background->blue;
3094
}
3095
}
3096
}
3097
}
3098
else /* if (row_info->bit_depth == 16) */
3099
{
3100
#ifdef PNG_READ_GAMMA_SUPPORTED
3101
if (gamma_16 != NULL)
3102
{
3103
sp = row;
3104
for (i = 0; i < row_width; i++, sp += 6)
3105
{
3106
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
3107
png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
3108
png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
3109
if (r == trans_values->red && g == trans_values->green &&
3110
b == trans_values->blue)
3111
{
3112
/* Background is already in screen gamma */
3113
*sp = (png_byte)((background->red >> 8) & 0xff);
3114
*(sp + 1) = (png_byte)(background->red & 0xff);
3115
*(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
3116
*(sp + 3) = (png_byte)(background->green & 0xff);
3117
*(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
3118
*(sp + 5) = (png_byte)(background->blue & 0xff);
3119
}
3120
else
3121
{
3122
png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
3123
*sp = (png_byte)((v >> 8) & 0xff);
3124
*(sp + 1) = (png_byte)(v & 0xff);
3125
v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
3126
*(sp + 2) = (png_byte)((v >> 8) & 0xff);
3127
*(sp + 3) = (png_byte)(v & 0xff);
3128
v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
3129
*(sp + 4) = (png_byte)((v >> 8) & 0xff);
3130
*(sp + 5) = (png_byte)(v & 0xff);
3131
}
3132
}
3133
}
3134
else
3135
#endif
3136
{
3137
sp = row;
3138
for (i = 0; i < row_width; i++, sp += 6)
3139
{
3140
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));
3141
png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
3142
png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
3143
3144
if (r == trans_values->red && g == trans_values->green &&
3145
b == trans_values->blue)
3146
{
3147
*sp = (png_byte)((background->red >> 8) & 0xff);
3148
*(sp + 1) = (png_byte)(background->red & 0xff);
3149
*(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
3150
*(sp + 3) = (png_byte)(background->green & 0xff);
3151
*(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
3152
*(sp + 5) = (png_byte)(background->blue & 0xff);
3153
}
3154
}
3155
}
3156
}
3157
break;
3158
}
3159
3160
case PNG_COLOR_TYPE_GRAY_ALPHA:
3161
{
3162
if (row_info->bit_depth == 8)
3163
{
3164
#ifdef PNG_READ_GAMMA_SUPPORTED
3165
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
3166
gamma_table != NULL)
3167
{
3168
sp = row;
3169
dp = row;
3170
for (i = 0; i < row_width; i++, sp += 2, dp++)
3171
{
3172
png_uint_16 a = *(sp + 1);
3173
3174
if (a == 0xff)
3175
{
3176
*dp = gamma_table[*sp];
3177
}
3178
else if (a == 0)
3179
{
3180
/* Background is already in screen gamma */
3181
*dp = (png_byte)background->gray;
3182
}
3183
else
3184
{
3185
png_byte v, w;
3186
3187
v = gamma_to_1[*sp];
3188
png_composite(w, v, a, background_1->gray);
3189
*dp = gamma_from_1[w];
3190
}
3191
}
3192
}
3193
else
3194
#endif
3195
{
3196
sp = row;
3197
dp = row;
3198
for (i = 0; i < row_width; i++, sp += 2, dp++)
3199
{
3200
png_byte a = *(sp + 1);
3201
3202
if (a == 0xff)
3203
{
3204
*dp = *sp;
3205
}
3206
#ifdef PNG_READ_GAMMA_SUPPORTED
3207
else if (a == 0)
3208
{
3209
*dp = (png_byte)background->gray;
3210
}
3211
else
3212
{
3213
png_composite(*dp, *sp, a, background_1->gray);
3214
}
3215
#else
3216
*dp = (png_byte)background->gray;
3217
#endif
3218
}
3219
}
3220
}
3221
else /* if (png_ptr->bit_depth == 16) */
3222
{
3223
#ifdef PNG_READ_GAMMA_SUPPORTED
3224
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
3225
gamma_16_to_1 != NULL)
3226
{
3227
sp = row;
3228
dp = row;
3229
for (i = 0; i < row_width; i++, sp += 4, dp += 2)
3230
{
3231
png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
3232
3233
if (a == (png_uint_16)0xffff)
3234
{
3235
png_uint_16 v;
3236
3237
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
3238
*dp = (png_byte)((v >> 8) & 0xff);
3239
*(dp + 1) = (png_byte)(v & 0xff);
3240
}
3241
#ifdef PNG_READ_GAMMA_SUPPORTED
3242
else if (a == 0)
3243
#else
3244
else
3245
#endif
3246
{
3247
/* Background is already in screen gamma */
3248
*dp = (png_byte)((background->gray >> 8) & 0xff);
3249
*(dp + 1) = (png_byte)(background->gray & 0xff);
3250
}
3251
#ifdef PNG_READ_GAMMA_SUPPORTED
3252
else
3253
{
3254
png_uint_16 g, v, w;
3255
3256
g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
3257
png_composite_16(v, g, a, background_1->gray);
3258
w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
3259
*dp = (png_byte)((w >> 8) & 0xff);
3260
*(dp + 1) = (png_byte)(w & 0xff);
3261
}
3262
#endif
3263
}
3264
}
3265
else
3266
#endif
3267
{
3268
sp = row;
3269
dp = row;
3270
for (i = 0; i < row_width; i++, sp += 4, dp += 2)
3271
{
3272
png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
3273
if (a == (png_uint_16)0xffff)
3274
{
3275
png_memcpy(dp, sp, 2);
3276
}
3277
#ifdef PNG_READ_GAMMA_SUPPORTED
3278
else if (a == 0)
3279
#else
3280
else
3281
#endif
3282
{
3283
*dp = (png_byte)((background->gray >> 8) & 0xff);
3284
*(dp + 1) = (png_byte)(background->gray & 0xff);
3285
}
3286
#ifdef PNG_READ_GAMMA_SUPPORTED
3287
else
3288
{
3289
png_uint_16 g, v;
3290
3291
g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
3292
png_composite_16(v, g, a, background_1->gray);
3293
*dp = (png_byte)((v >> 8) & 0xff);
3294
*(dp + 1) = (png_byte)(v & 0xff);
3295
}
3296
#endif
3297
}
3298
}
3299
}
3300
break;
3301
}
3302
3303
case PNG_COLOR_TYPE_RGB_ALPHA:
3304
{
3305
if (row_info->bit_depth == 8)
3306
{
3307
#ifdef PNG_READ_GAMMA_SUPPORTED
3308
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
3309
gamma_table != NULL)
3310
{
3311
sp = row;
3312
dp = row;
3313
for (i = 0; i < row_width; i++, sp += 4, dp += 3)
3314
{
3315
png_byte a = *(sp + 3);
3316
3317
if (a == 0xff)
3318
{
3319
*dp = gamma_table[*sp];
3320
*(dp + 1) = gamma_table[*(sp + 1)];
3321
*(dp + 2) = gamma_table[*(sp + 2)];
3322
}
3323
else if (a == 0)
3324
{
3325
/* Background is already in screen gamma */
3326
*dp = (png_byte)background->red;
3327
*(dp + 1) = (png_byte)background->green;
3328
*(dp + 2) = (png_byte)background->blue;
3329
}
3330
else
3331
{
3332
png_byte v, w;
3333
3334
v = gamma_to_1[*sp];
3335
png_composite(w, v, a, background_1->red);
3336
*dp = gamma_from_1[w];
3337
v = gamma_to_1[*(sp + 1)];
3338
png_composite(w, v, a, background_1->green);
3339
*(dp + 1) = gamma_from_1[w];
3340
v = gamma_to_1[*(sp + 2)];
3341
png_composite(w, v, a, background_1->blue);
3342
*(dp + 2) = gamma_from_1[w];
3343
}
3344
}
3345
}
3346
else
3347
#endif
3348
{
3349
sp = row;
3350
dp = row;
3351
for (i = 0; i < row_width; i++, sp += 4, dp += 3)
3352
{
3353
png_byte a = *(sp + 3);
3354
3355
if (a == 0xff)
3356
{
3357
*dp = *sp;
3358
*(dp + 1) = *(sp + 1);
3359
*(dp + 2) = *(sp + 2);
3360
}
3361
else if (a == 0)
3362
{
3363
*dp = (png_byte)background->red;
3364
*(dp + 1) = (png_byte)background->green;
3365
*(dp + 2) = (png_byte)background->blue;
3366
}
3367
else
3368
{
3369
png_composite(*dp, *sp, a, background->red);
3370
png_composite(*(dp + 1), *(sp + 1), a,
3371
background->green);
3372
png_composite(*(dp + 2), *(sp + 2), a,
3373
background->blue);
3374
}
3375
}
3376
}
3377
}
3378
else /* if (row_info->bit_depth == 16) */
3379
{
3380
#ifdef PNG_READ_GAMMA_SUPPORTED
3381
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
3382
gamma_16_to_1 != NULL)
3383
{
3384
sp = row;
3385
dp = row;
3386
for (i = 0; i < row_width; i++, sp += 8, dp += 6)
3387
{
3388
png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
3389
<< 8) + (png_uint_16)(*(sp + 7)));
3390
if (a == (png_uint_16)0xffff)
3391
{
3392
png_uint_16 v;
3393
3394
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
3395
*dp = (png_byte)((v >> 8) & 0xff);
3396
*(dp + 1) = (png_byte)(v & 0xff);
3397
v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
3398
*(dp + 2) = (png_byte)((v >> 8) & 0xff);
3399
*(dp + 3) = (png_byte)(v & 0xff);
3400
v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
3401
*(dp + 4) = (png_byte)((v >> 8) & 0xff);
3402
*(dp + 5) = (png_byte)(v & 0xff);
3403
}
3404
else if (a == 0)
3405
{
3406
/* Background is already in screen gamma */
3407
*dp = (png_byte)((background->red >> 8) & 0xff);
3408
*(dp + 1) = (png_byte)(background->red & 0xff);
3409
*(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
3410
*(dp + 3) = (png_byte)(background->green & 0xff);
3411
*(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
3412
*(dp + 5) = (png_byte)(background->blue & 0xff);
3413
}
3414
else
3415
{
3416
png_uint_16 v, w, x;
3417
3418
v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
3419
png_composite_16(w, v, a, background_1->red);
3420
x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
3421
*dp = (png_byte)((x >> 8) & 0xff);
3422
*(dp + 1) = (png_byte)(x & 0xff);
3423
v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
3424
png_composite_16(w, v, a, background_1->green);
3425
x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
3426
*(dp + 2) = (png_byte)((x >> 8) & 0xff);
3427
*(dp + 3) = (png_byte)(x & 0xff);
3428
v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
3429
png_composite_16(w, v, a, background_1->blue);
3430
x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
3431
*(dp + 4) = (png_byte)((x >> 8) & 0xff);
3432
*(dp + 5) = (png_byte)(x & 0xff);
3433
}
3434
}
3435
}
3436
else
3437
#endif
3438
{
3439
sp = row;
3440
dp = row;
3441
for (i = 0; i < row_width; i++, sp += 8, dp += 6)
3442
{
3443
png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
3444
<< 8) + (png_uint_16)(*(sp + 7)));
3445
if (a == (png_uint_16)0xffff)
3446
{
3447
png_memcpy(dp, sp, 6);
3448
}
3449
else if (a == 0)
3450
{
3451
*dp = (png_byte)((background->red >> 8) & 0xff);
3452
*(dp + 1) = (png_byte)(background->red & 0xff);
3453
*(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
3454
*(dp + 3) = (png_byte)(background->green & 0xff);
3455
*(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
3456
*(dp + 5) = (png_byte)(background->blue & 0xff);
3457
}
3458
else
3459
{
3460
png_uint_16 v;
3461
3462
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
3463
png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
3464
+ *(sp + 3));
3465
png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
3466
+ *(sp + 5));
3467
3468
png_composite_16(v, r, a, background->red);
3469
*dp = (png_byte)((v >> 8) & 0xff);
3470
*(dp + 1) = (png_byte)(v & 0xff);
3471
png_composite_16(v, g, a, background->green);
3472
*(dp + 2) = (png_byte)((v >> 8) & 0xff);
3473
*(dp + 3) = (png_byte)(v & 0xff);
3474
png_composite_16(v, b, a, background->blue);
3475
*(dp + 4) = (png_byte)((v >> 8) & 0xff);
3476
*(dp + 5) = (png_byte)(v & 0xff);
3477
}
3478
}
3479
}
3480
}
3481
break;
3482
}
3483
}
3484
3485
if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
3486
{
3487
row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
3488
row_info->channels--;
3489
row_info->pixel_depth = (png_byte)(row_info->channels *
3490
row_info->bit_depth);
3491
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
3492
}
3493
}
3494
}
3495
#endif
3496
3497
#ifdef PNG_READ_GAMMA_SUPPORTED
3498
/* Gamma correct the image, avoiding the alpha channel. Make sure
3499
* you do this after you deal with the transparency issue on grayscale
3500
* or RGB images. If your bit depth is 8, use gamma_table, if it
3501
* is 16, use gamma_16_table and gamma_shift. Build these with
3502
* build_gamma_table().
3503
*/
3504
void /* PRIVATE */
3505
png_do_gamma(png_row_infop row_info, png_bytep row,
3506
png_bytep gamma_table, png_uint_16pp gamma_16_table,
3507
int gamma_shift)
3508
{
3509
png_bytep sp;
3510
png_uint_32 i;
3511
png_uint_32 row_width=row_info->width;
3512
3513
png_debug(1, "in png_do_gamma");
3514
3515
if (
3516
#ifdef PNG_USELESS_TESTS_SUPPORTED
3517
row != NULL && row_info != NULL &&
3518
#endif
3519
((row_info->bit_depth <= 8 && gamma_table != NULL) ||
3520
(row_info->bit_depth == 16 && gamma_16_table != NULL)))
3521
{
3522
switch (row_info->color_type)
3523
{
3524
case PNG_COLOR_TYPE_RGB:
3525
{
3526
if (row_info->bit_depth == 8)
3527
{
3528
sp = row;
3529
for (i = 0; i < row_width; i++)
3530
{
3531
*sp = gamma_table[*sp];
3532
sp++;
3533
*sp = gamma_table[*sp];
3534
sp++;
3535
*sp = gamma_table[*sp];
3536
sp++;
3537
}
3538
}
3539
else /* if (row_info->bit_depth == 16) */
3540
{
3541
sp = row;
3542
for (i = 0; i < row_width; i++)
3543
{
3544
png_uint_16 v;
3545
3546
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3547
*sp = (png_byte)((v >> 8) & 0xff);
3548
*(sp + 1) = (png_byte)(v & 0xff);
3549
sp += 2;
3550
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3551
*sp = (png_byte)((v >> 8) & 0xff);
3552
*(sp + 1) = (png_byte)(v & 0xff);
3553
sp += 2;
3554
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3555
*sp = (png_byte)((v >> 8) & 0xff);
3556
*(sp + 1) = (png_byte)(v & 0xff);
3557
sp += 2;
3558
}
3559
}
3560
break;
3561
}
3562
3563
case PNG_COLOR_TYPE_RGB_ALPHA:
3564
{
3565
if (row_info->bit_depth == 8)
3566
{
3567
sp = row;
3568
for (i = 0; i < row_width; i++)
3569
{
3570
*sp = gamma_table[*sp];
3571
sp++;
3572
*sp = gamma_table[*sp];
3573
sp++;
3574
*sp = gamma_table[*sp];
3575
sp++;
3576
sp++;
3577
}
3578
}
3579
else /* if (row_info->bit_depth == 16) */
3580
{
3581
sp = row;
3582
for (i = 0; i < row_width; i++)
3583
{
3584
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3585
*sp = (png_byte)((v >> 8) & 0xff);
3586
*(sp + 1) = (png_byte)(v & 0xff);
3587
sp += 2;
3588
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3589
*sp = (png_byte)((v >> 8) & 0xff);
3590
*(sp + 1) = (png_byte)(v & 0xff);
3591
sp += 2;
3592
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3593
*sp = (png_byte)((v >> 8) & 0xff);
3594
*(sp + 1) = (png_byte)(v & 0xff);
3595
sp += 4;
3596
}
3597
}
3598
break;
3599
}
3600
3601
case PNG_COLOR_TYPE_GRAY_ALPHA:
3602
{
3603
if (row_info->bit_depth == 8)
3604
{
3605
sp = row;
3606
for (i = 0; i < row_width; i++)
3607
{
3608
*sp = gamma_table[*sp];
3609
sp += 2;
3610
}
3611
}
3612
else /* if (row_info->bit_depth == 16) */
3613
{
3614
sp = row;
3615
for (i = 0; i < row_width; i++)
3616
{
3617
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3618
*sp = (png_byte)((v >> 8) & 0xff);
3619
*(sp + 1) = (png_byte)(v & 0xff);
3620
sp += 4;
3621
}
3622
}
3623
break;
3624
}
3625
3626
case PNG_COLOR_TYPE_GRAY:
3627
{
3628
if (row_info->bit_depth == 2)
3629
{
3630
sp = row;
3631
for (i = 0; i < row_width; i += 4)
3632
{
3633
int a = *sp & 0xc0;
3634
int b = *sp & 0x30;
3635
int c = *sp & 0x0c;
3636
int d = *sp & 0x03;
3637
3638
*sp = (png_byte)(
3639
((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
3640
((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
3641
((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
3642
((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
3643
sp++;
3644
}
3645
}
3646
3647
if (row_info->bit_depth == 4)
3648
{
3649
sp = row;
3650
for (i = 0; i < row_width; i += 2)
3651
{
3652
int msb = *sp & 0xf0;
3653
int lsb = *sp & 0x0f;
3654
3655
*sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
3656
| (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
3657
sp++;
3658
}
3659
}
3660
3661
else if (row_info->bit_depth == 8)
3662
{
3663
sp = row;
3664
for (i = 0; i < row_width; i++)
3665
{
3666
*sp = gamma_table[*sp];
3667
sp++;
3668
}
3669
}
3670
3671
else if (row_info->bit_depth == 16)
3672
{
3673
sp = row;
3674
for (i = 0; i < row_width; i++)
3675
{
3676
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
3677
*sp = (png_byte)((v >> 8) & 0xff);
3678
*(sp + 1) = (png_byte)(v & 0xff);
3679
sp += 2;
3680
}
3681
}
3682
break;
3683
}
3684
}
3685
}
3686
}
3687
#endif
3688
3689
#ifdef PNG_READ_EXPAND_SUPPORTED
3690
/* Expands a palette row to an RGB or RGBA row depending
3691
* upon whether you supply trans and num_trans.
3692
*/
3693
void /* PRIVATE */
3694
png_do_expand_palette(png_row_infop row_info, png_bytep row,
3695
png_colorp palette, png_bytep trans, int num_trans)
3696
{
3697
int shift, value;
3698
png_bytep sp, dp;
3699
png_uint_32 i;
3700
png_uint_32 row_width=row_info->width;
3701
3702
png_debug(1, "in png_do_expand_palette");
3703
3704
if (
3705
#ifdef PNG_USELESS_TESTS_SUPPORTED
3706
row != NULL && row_info != NULL &&
3707
#endif
3708
row_info->color_type == PNG_COLOR_TYPE_PALETTE)
3709
{
3710
if (row_info->bit_depth < 8)
3711
{
3712
switch (row_info->bit_depth)
3713
{
3714
case 1:
3715
{
3716
sp = row + (png_size_t)((row_width - 1) >> 3);
3717
dp = row + (png_size_t)row_width - 1;
3718
shift = 7 - (int)((row_width + 7) & 0x07);
3719
for (i = 0; i < row_width; i++)
3720
{
3721
if ((*sp >> shift) & 0x01)
3722
*dp = 1;
3723
else
3724
*dp = 0;
3725
if (shift == 7)
3726
{
3727
shift = 0;
3728
sp--;
3729
}
3730
else
3731
shift++;
3732
3733
dp--;
3734
}
3735
break;
3736
}
3737
3738
case 2:
3739
{
3740
sp = row + (png_size_t)((row_width - 1) >> 2);
3741
dp = row + (png_size_t)row_width - 1;
3742
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
3743
for (i = 0; i < row_width; i++)
3744
{
3745
value = (*sp >> shift) & 0x03;
3746
*dp = (png_byte)value;
3747
if (shift == 6)
3748
{
3749
shift = 0;
3750
sp--;
3751
}
3752
else
3753
shift += 2;
3754
3755
dp--;
3756
}
3757
break;
3758
}
3759
3760
case 4:
3761
{
3762
sp = row + (png_size_t)((row_width - 1) >> 1);
3763
dp = row + (png_size_t)row_width - 1;
3764
shift = (int)((row_width & 0x01) << 2);
3765
for (i = 0; i < row_width; i++)
3766
{
3767
value = (*sp >> shift) & 0x0f;
3768
*dp = (png_byte)value;
3769
if (shift == 4)
3770
{
3771
shift = 0;
3772
sp--;
3773
}
3774
else
3775
shift += 4;
3776
3777
dp--;
3778
}
3779
break;
3780
}
3781
}
3782
row_info->bit_depth = 8;
3783
row_info->pixel_depth = 8;
3784
row_info->rowbytes = row_width;
3785
}
3786
switch (row_info->bit_depth)
3787
{
3788
case 8:
3789
{
3790
if (trans != NULL)
3791
{
3792
sp = row + (png_size_t)row_width - 1;
3793
dp = row + (png_size_t)(row_width << 2) - 1;
3794
3795
for (i = 0; i < row_width; i++)
3796
{
3797
if ((int)(*sp) >= num_trans)
3798
*dp-- = 0xff;
3799
else
3800
*dp-- = trans[*sp];
3801
*dp-- = palette[*sp].blue;
3802
*dp-- = palette[*sp].green;
3803
*dp-- = palette[*sp].red;
3804
sp--;
3805
}
3806
row_info->bit_depth = 8;
3807
row_info->pixel_depth = 32;
3808
row_info->rowbytes = row_width * 4;
3809
row_info->color_type = 6;
3810
row_info->channels = 4;
3811
}
3812
else
3813
{
3814
sp = row + (png_size_t)row_width - 1;
3815
dp = row + (png_size_t)(row_width * 3) - 1;
3816
3817
for (i = 0; i < row_width; i++)
3818
{
3819
*dp-- = palette[*sp].blue;
3820
*dp-- = palette[*sp].green;
3821
*dp-- = palette[*sp].red;
3822
sp--;
3823
}
3824
3825
row_info->bit_depth = 8;
3826
row_info->pixel_depth = 24;
3827
row_info->rowbytes = row_width * 3;
3828
row_info->color_type = 2;
3829
row_info->channels = 3;
3830
}
3831
break;
3832
}
3833
}
3834
}
3835
}
3836
3837
/* If the bit depth < 8, it is expanded to 8. Also, if the already
3838
* expanded transparency value is supplied, an alpha channel is built.
3839
*/
3840
void /* PRIVATE */
3841
png_do_expand(png_row_infop row_info, png_bytep row,
3842
png_color_16p trans_value)
3843
{
3844
int shift, value;
3845
png_bytep sp, dp;
3846
png_uint_32 i;
3847
png_uint_32 row_width=row_info->width;
3848
3849
png_debug(1, "in png_do_expand");
3850
3851
#ifdef PNG_USELESS_TESTS_SUPPORTED
3852
if (row != NULL && row_info != NULL)
3853
#endif
3854
{
3855
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
3856
{
3857
png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
3858
3859
if (row_info->bit_depth < 8)
3860
{
3861
switch (row_info->bit_depth)
3862
{
3863
case 1:
3864
{
3865
gray = (png_uint_16)((gray&0x01)*0xff);
3866
sp = row + (png_size_t)((row_width - 1) >> 3);
3867
dp = row + (png_size_t)row_width - 1;
3868
shift = 7 - (int)((row_width + 7) & 0x07);
3869
for (i = 0; i < row_width; i++)
3870
{
3871
if ((*sp >> shift) & 0x01)
3872
*dp = 0xff;
3873
else
3874
*dp = 0;
3875
if (shift == 7)
3876
{
3877
shift = 0;
3878
sp--;
3879
}
3880
else
3881
shift++;
3882
3883
dp--;
3884
}
3885
break;
3886
}
3887
3888
case 2:
3889
{
3890
gray = (png_uint_16)((gray&0x03)*0x55);
3891
sp = row + (png_size_t)((row_width - 1) >> 2);
3892
dp = row + (png_size_t)row_width - 1;
3893
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
3894
for (i = 0; i < row_width; i++)
3895
{
3896
value = (*sp >> shift) & 0x03;
3897
*dp = (png_byte)(value | (value << 2) | (value << 4) |
3898
(value << 6));
3899
if (shift == 6)
3900
{
3901
shift = 0;
3902
sp--;
3903
}
3904
else
3905
shift += 2;
3906
3907
dp--;
3908
}
3909
break;
3910
}
3911
3912
case 4:
3913
{
3914
gray = (png_uint_16)((gray&0x0f)*0x11);
3915
sp = row + (png_size_t)((row_width - 1) >> 1);
3916
dp = row + (png_size_t)row_width - 1;
3917
shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
3918
for (i = 0; i < row_width; i++)
3919
{
3920
value = (*sp >> shift) & 0x0f;
3921
*dp = (png_byte)(value | (value << 4));
3922
if (shift == 4)
3923
{
3924
shift = 0;
3925
sp--;
3926
}
3927
else
3928
shift = 4;
3929
3930
dp--;
3931
}
3932
break;
3933
}
3934
}
3935
3936
row_info->bit_depth = 8;
3937
row_info->pixel_depth = 8;
3938
row_info->rowbytes = row_width;
3939
}
3940
3941
if (trans_value != NULL)
3942
{
3943
if (row_info->bit_depth == 8)
3944
{
3945
gray = gray & 0xff;
3946
sp = row + (png_size_t)row_width - 1;
3947
dp = row + (png_size_t)(row_width << 1) - 1;
3948
for (i = 0; i < row_width; i++)
3949
{
3950
if (*sp == gray)
3951
*dp-- = 0;
3952
else
3953
*dp-- = 0xff;
3954
*dp-- = *sp--;
3955
}
3956
}
3957
3958
else if (row_info->bit_depth == 16)
3959
{
3960
png_byte gray_high = (gray >> 8) & 0xff;
3961
png_byte gray_low = gray & 0xff;
3962
sp = row + row_info->rowbytes - 1;
3963
dp = row + (row_info->rowbytes << 1) - 1;
3964
for (i = 0; i < row_width; i++)
3965
{
3966
if (*(sp - 1) == gray_high && *(sp) == gray_low)
3967
{
3968
*dp-- = 0;
3969
*dp-- = 0;
3970
}
3971
else
3972
{
3973
*dp-- = 0xff;
3974
*dp-- = 0xff;
3975
}
3976
*dp-- = *sp--;
3977
*dp-- = *sp--;
3978
}
3979
}
3980
3981
row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
3982
row_info->channels = 2;
3983
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
3984
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
3985
row_width);
3986
}
3987
}
3988
else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
3989
{
3990
if (row_info->bit_depth == 8)
3991
{
3992
png_byte red = trans_value->red & 0xff;
3993
png_byte green = trans_value->green & 0xff;
3994
png_byte blue = trans_value->blue & 0xff;
3995
sp = row + (png_size_t)row_info->rowbytes - 1;
3996
dp = row + (png_size_t)(row_width << 2) - 1;
3997
for (i = 0; i < row_width; i++)
3998
{
3999
if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
4000
*dp-- = 0;
4001
else
4002
*dp-- = 0xff;
4003
*dp-- = *sp--;
4004
*dp-- = *sp--;
4005
*dp-- = *sp--;
4006
}
4007
}
4008
else if (row_info->bit_depth == 16)
4009
{
4010
png_byte red_high = (trans_value->red >> 8) & 0xff;
4011
png_byte green_high = (trans_value->green >> 8) & 0xff;
4012
png_byte blue_high = (trans_value->blue >> 8) & 0xff;
4013
png_byte red_low = trans_value->red & 0xff;
4014
png_byte green_low = trans_value->green & 0xff;
4015
png_byte blue_low = trans_value->blue & 0xff;
4016
sp = row + row_info->rowbytes - 1;
4017
dp = row + (png_size_t)(row_width << 3) - 1;
4018
for (i = 0; i < row_width; i++)
4019
{
4020
if (*(sp - 5) == red_high &&
4021
*(sp - 4) == red_low &&
4022
*(sp - 3) == green_high &&
4023
*(sp - 2) == green_low &&
4024
*(sp - 1) == blue_high &&
4025
*(sp ) == blue_low)
4026
{
4027
*dp-- = 0;
4028
*dp-- = 0;
4029
}
4030
else
4031
{
4032
*dp-- = 0xff;
4033
*dp-- = 0xff;
4034
}
4035
*dp-- = *sp--;
4036
*dp-- = *sp--;
4037
*dp-- = *sp--;
4038
*dp-- = *sp--;
4039
*dp-- = *sp--;
4040
*dp-- = *sp--;
4041
}
4042
}
4043
row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
4044
row_info->channels = 4;
4045
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
4046
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
4047
}
4048
}
4049
}
4050
#endif
4051
4052
#ifdef PNG_READ_DITHER_SUPPORTED
4053
void /* PRIVATE */
4054
png_do_dither(png_row_infop row_info, png_bytep row,
4055
png_bytep palette_lookup, png_bytep dither_lookup)
4056
{
4057
png_bytep sp, dp;
4058
png_uint_32 i;
4059
png_uint_32 row_width=row_info->width;
4060
4061
png_debug(1, "in png_do_dither");
4062
4063
#ifdef PNG_USELESS_TESTS_SUPPORTED
4064
if (row != NULL && row_info != NULL)
4065
#endif
4066
{
4067
if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
4068
palette_lookup && row_info->bit_depth == 8)
4069
{
4070
int r, g, b, p;
4071
sp = row;
4072
dp = row;
4073
for (i = 0; i < row_width; i++)
4074
{
4075
r = *sp++;
4076
g = *sp++;
4077
b = *sp++;
4078
4079
/* This looks real messy, but the compiler will reduce
4080
* it down to a reasonable formula. For example, with
4081
* 5 bits per color, we get:
4082
* p = (((r >> 3) & 0x1f) << 10) |
4083
* (((g >> 3) & 0x1f) << 5) |
4084
* ((b >> 3) & 0x1f);
4085
*/
4086
p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
4087
((1 << PNG_DITHER_RED_BITS) - 1)) <<
4088
(PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
4089
(((g >> (8 - PNG_DITHER_GREEN_BITS)) &
4090
((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
4091
(PNG_DITHER_BLUE_BITS)) |
4092
((b >> (8 - PNG_DITHER_BLUE_BITS)) &
4093
((1 << PNG_DITHER_BLUE_BITS) - 1));
4094
4095
*dp++ = palette_lookup[p];
4096
}
4097
row_info->color_type = PNG_COLOR_TYPE_PALETTE;
4098
row_info->channels = 1;
4099
row_info->pixel_depth = row_info->bit_depth;
4100
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
4101
}
4102
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
4103
palette_lookup != NULL && row_info->bit_depth == 8)
4104
{
4105
int r, g, b, p;
4106
sp = row;
4107
dp = row;
4108
for (i = 0; i < row_width; i++)
4109
{
4110
r = *sp++;
4111
g = *sp++;
4112
b = *sp++;
4113
sp++;
4114
4115
p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
4116
((1 << PNG_DITHER_RED_BITS) - 1)) <<
4117
(PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
4118
(((g >> (8 - PNG_DITHER_GREEN_BITS)) &
4119
((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
4120
(PNG_DITHER_BLUE_BITS)) |
4121
((b >> (8 - PNG_DITHER_BLUE_BITS)) &
4122
((1 << PNG_DITHER_BLUE_BITS) - 1));
4123
4124
*dp++ = palette_lookup[p];
4125
}
4126
row_info->color_type = PNG_COLOR_TYPE_PALETTE;
4127
row_info->channels = 1;
4128
row_info->pixel_depth = row_info->bit_depth;
4129
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
4130
}
4131
else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
4132
dither_lookup && row_info->bit_depth == 8)
4133
{
4134
sp = row;
4135
for (i = 0; i < row_width; i++, sp++)
4136
{
4137
*sp = dither_lookup[*sp];
4138
}
4139
}
4140
}
4141
}
4142
#endif
4143
4144
#ifdef PNG_FLOATING_POINT_SUPPORTED
4145
#ifdef PNG_READ_GAMMA_SUPPORTED
4146
static PNG_CONST int png_gamma_shift[] =
4147
{0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
4148
4149
/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
4150
* tables, we don't make a full table if we are reducing to 8-bit in
4151
* the future. Note also how the gamma_16 tables are segmented so that
4152
* we don't need to allocate > 64K chunks for a full 16-bit table.
4153
*
4154
* See the PNG extensions document for an integer algorithm for creating
4155
* the gamma tables. Maybe we will implement that here someday.
4156
*
4157
* We should only reach this point if
4158
*
4159
* the file_gamma is known (i.e., the gAMA or sRGB chunk is present,
4160
* or the application has provided a file_gamma)
4161
*
4162
* AND
4163
* {
4164
* the screen_gamma is known
4165
* OR
4166
*
4167
* RGB_to_gray transformation is being performed
4168
* }
4169
*
4170
* AND
4171
* {
4172
* the screen_gamma is different from the reciprocal of the
4173
* file_gamma by more than the specified threshold
4174
*
4175
* OR
4176
*
4177
* a background color has been specified and the file_gamma
4178
* and screen_gamma are not 1.0, within the specified threshold.
4179
* }
4180
*/
4181
4182
void /* PRIVATE */
4183
png_build_gamma_table(png_structp png_ptr)
4184
{
4185
png_debug(1, "in png_build_gamma_table");
4186
4187
if (png_ptr->bit_depth <= 8)
4188
{
4189
int i;
4190
double g;
4191
4192
if (png_ptr->screen_gamma > .000001)
4193
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
4194
4195
else
4196
g = 1.0;
4197
4198
png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
4199
(png_uint_32)256);
4200
4201
for (i = 0; i < 256; i++)
4202
{
4203
png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
4204
g) * 255.0 + .5);
4205
}
4206
4207
#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
4208
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
4209
if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
4210
{
4211
4212
g = 1.0 / (png_ptr->gamma);
4213
4214
png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
4215
(png_uint_32)256);
4216
4217
for (i = 0; i < 256; i++)
4218
{
4219
png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
4220
g) * 255.0 + .5);
4221
}
4222
4223
4224
png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
4225
(png_uint_32)256);
4226
4227
if (png_ptr->screen_gamma > 0.000001)
4228
g = 1.0 / png_ptr->screen_gamma;
4229
4230
else
4231
g = png_ptr->gamma; /* Probably doing rgb_to_gray */
4232
4233
for (i = 0; i < 256; i++)
4234
{
4235
png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
4236
g) * 255.0 + .5);
4237
4238
}
4239
}
4240
#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
4241
}
4242
else
4243
{
4244
double g;
4245
int i, j, shift, num;
4246
int sig_bit;
4247
png_uint_32 ig;
4248
4249
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
4250
{
4251
sig_bit = (int)png_ptr->sig_bit.red;
4252
4253
if ((int)png_ptr->sig_bit.green > sig_bit)
4254
sig_bit = png_ptr->sig_bit.green;
4255
4256
if ((int)png_ptr->sig_bit.blue > sig_bit)
4257
sig_bit = png_ptr->sig_bit.blue;
4258
}
4259
else
4260
{
4261
sig_bit = (int)png_ptr->sig_bit.gray;
4262
}
4263
4264
if (sig_bit > 0)
4265
shift = 16 - sig_bit;
4266
4267
else
4268
shift = 0;
4269
4270
if (png_ptr->transformations & PNG_16_TO_8)
4271
{
4272
if (shift < (16 - PNG_MAX_GAMMA_8))
4273
shift = (16 - PNG_MAX_GAMMA_8);
4274
}
4275
4276
if (shift > 8)
4277
shift = 8;
4278
4279
if (shift < 0)
4280
shift = 0;
4281
4282
png_ptr->gamma_shift = (png_byte)shift;
4283
4284
num = (1 << (8 - shift));
4285
4286
if (png_ptr->screen_gamma > .000001)
4287
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
4288
else
4289
g = 1.0;
4290
4291
png_ptr->gamma_16_table = (png_uint_16pp)png_calloc(png_ptr,
4292
(png_uint_32)(num * png_sizeof(png_uint_16p)));
4293
4294
if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
4295
{
4296
double fin, fout;
4297
png_uint_32 last, max;
4298
4299
for (i = 0; i < num; i++)
4300
{
4301
png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
4302
(png_uint_32)(256 * png_sizeof(png_uint_16)));
4303
}
4304
4305
g = 1.0 / g;
4306
last = 0;
4307
for (i = 0; i < 256; i++)
4308
{
4309
fout = ((double)i + 0.5) / 256.0;
4310
fin = pow(fout, g);
4311
max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));
4312
while (last <= max)
4313
{
4314
png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
4315
[(int)(last >> (8 - shift))] = (png_uint_16)(
4316
(png_uint_16)i | ((png_uint_16)i << 8));
4317
last++;
4318
}
4319
}
4320
while (last < ((png_uint_32)num << 8))
4321
{
4322
png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
4323
[(int)(last >> (8 - shift))] = (png_uint_16)65535L;
4324
last++;
4325
}
4326
}
4327
else
4328
{
4329
for (i = 0; i < num; i++)
4330
{
4331
png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
4332
(png_uint_32)(256 * png_sizeof(png_uint_16)));
4333
4334
ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
4335
4336
for (j = 0; j < 256; j++)
4337
{
4338
png_ptr->gamma_16_table[i][j] =
4339
(png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
4340
65535.0, g) * 65535.0 + .5);
4341
}
4342
}
4343
}
4344
4345
#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
4346
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
4347
if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
4348
{
4349
4350
g = 1.0 / (png_ptr->gamma);
4351
4352
png_ptr->gamma_16_to_1 = (png_uint_16pp)png_calloc(png_ptr,
4353
(png_uint_32)(num * png_sizeof(png_uint_16p )));
4354
4355
for (i = 0; i < num; i++)
4356
{
4357
png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
4358
(png_uint_32)(256 * png_sizeof(png_uint_16)));
4359
4360
ig = (((png_uint_32)i *
4361
(png_uint_32)png_gamma_shift[shift]) >> 4);
4362
for (j = 0; j < 256; j++)
4363
{
4364
png_ptr->gamma_16_to_1[i][j] =
4365
(png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
4366
65535.0, g) * 65535.0 + .5);
4367
}
4368
}
4369
4370
if (png_ptr->screen_gamma > 0.000001)
4371
g = 1.0 / png_ptr->screen_gamma;
4372
4373
else
4374
g = png_ptr->gamma; /* Probably doing rgb_to_gray */
4375
4376
png_ptr->gamma_16_from_1 = (png_uint_16pp)png_calloc(png_ptr,
4377
(png_uint_32)(num * png_sizeof(png_uint_16p)));
4378
4379
for (i = 0; i < num; i++)
4380
{
4381
png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
4382
(png_uint_32)(256 * png_sizeof(png_uint_16)));
4383
4384
ig = (((png_uint_32)i *
4385
(png_uint_32)png_gamma_shift[shift]) >> 4);
4386
4387
for (j = 0; j < 256; j++)
4388
{
4389
png_ptr->gamma_16_from_1[i][j] =
4390
(png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
4391
65535.0, g) * 65535.0 + .5);
4392
}
4393
}
4394
}
4395
#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
4396
}
4397
}
4398
#endif
4399
/* To do: install integer version of png_build_gamma_table here */
4400
#endif
4401
4402
#ifdef PNG_MNG_FEATURES_SUPPORTED
4403
/* Undoes intrapixel differencing */
4404
void /* PRIVATE */
4405
png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
4406
{
4407
png_debug(1, "in png_do_read_intrapixel");
4408
4409
if (
4410
#ifdef PNG_USELESS_TESTS_SUPPORTED
4411
row != NULL && row_info != NULL &&
4412
#endif
4413
(row_info->color_type & PNG_COLOR_MASK_COLOR))
4414
{
4415
int bytes_per_pixel;
4416
png_uint_32 row_width = row_info->width;
4417
if (row_info->bit_depth == 8)
4418
{
4419
png_bytep rp;
4420
png_uint_32 i;
4421
4422
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
4423
bytes_per_pixel = 3;
4424
4425
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
4426
bytes_per_pixel = 4;
4427
4428
else
4429
return;
4430
4431
for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
4432
{
4433
*(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff);
4434
*(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff);
4435
}
4436
}
4437
else if (row_info->bit_depth == 16)
4438
{
4439
png_bytep rp;
4440
png_uint_32 i;
4441
4442
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
4443
bytes_per_pixel = 6;
4444
4445
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
4446
bytes_per_pixel = 8;
4447
4448
else
4449
return;
4450
4451
for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
4452
{
4453
png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
4454
png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
4455
png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
4456
png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);
4457
png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);
4458
*(rp ) = (png_byte)((red >> 8) & 0xff);
4459
*(rp+1) = (png_byte)(red & 0xff);
4460
*(rp+4) = (png_byte)((blue >> 8) & 0xff);
4461
*(rp+5) = (png_byte)(blue & 0xff);
4462
}
4463
}
4464
}
4465
}
4466
#endif /* PNG_MNG_FEATURES_SUPPORTED */
4467
#endif /* PNG_READ_SUPPORTED */
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