4
* Copyright (C) 1997-2009, Thomas G. Lane, Guido Vollbeding.
5
* This file is part of the Independent JPEG Group's software.
6
* For conditions of distribution and use, see the accompanying README file.
8
* This file contains image transformation routines and other utility code
9
* used by the jpegtran sample application. These are NOT part of the core
10
* JPEG library. But we keep these routines separate from jpegtran.c to
11
* ease the task of maintaining jpegtran-like programs that have other user
15
/* Although this file really shouldn't have access to the library internals,
16
* it's helpful to let it call jround_up() and jcopy_block_row().
18
#define JPEG_INTERNALS
22
#include "transupp.h" /* My own external interface */
23
#include <ctype.h> /* to declare isdigit() */
26
#if TRANSFORMS_SUPPORTED
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* Lossless image transformation routines. These routines work on DCT
30
* coefficient arrays and thus do not require any lossy decompression
31
* or recompression of the image.
32
* Thanks to Guido Vollbeding for the initial design and code of this feature,
33
* and to Ben Jackson for introducing the cropping feature.
35
* Horizontal flipping is done in-place, using a single top-to-bottom
36
* pass through the virtual source array. It will thus be much the
37
* fastest option for images larger than main memory.
39
* The other routines require a set of destination virtual arrays, so they
40
* need twice as much memory as jpegtran normally does. The destination
41
* arrays are always written in normal scan order (top to bottom) because
42
* the virtual array manager expects this. The source arrays will be scanned
43
* in the corresponding order, which means multiple passes through the source
44
* arrays for most of the transforms. That could result in much thrashing
45
* if the image is larger than main memory.
47
* If cropping or trimming is involved, the destination arrays may be smaller
48
* than the source arrays. Note it is not possible to do horizontal flip
49
* in-place when a nonzero Y crop offset is specified, since we'd have to move
50
* data from one block row to another but the virtual array manager doesn't
51
* guarantee we can touch more than one row at a time. So in that case,
52
* we have to use a separate destination array.
54
* Some notes about the operating environment of the individual transform
56
* 1. Both the source and destination virtual arrays are allocated from the
57
* source JPEG object, and therefore should be manipulated by calling the
58
* source's memory manager.
59
* 2. The destination's component count should be used. It may be smaller
60
* than the source's when forcing to grayscale.
61
* 3. Likewise the destination's sampling factors should be used. When
62
* forcing to grayscale the destination's sampling factors will be all 1,
63
* and we may as well take that as the effective iMCU size.
64
* 4. When "trim" is in effect, the destination's dimensions will be the
65
* trimmed values but the source's will be untrimmed.
66
* 5. When "crop" is in effect, the destination's dimensions will be the
67
* cropped values but the source's will be uncropped. Each transform
68
* routine is responsible for picking up source data starting at the
69
* correct X and Y offset for the crop region. (The X and Y offsets
70
* passed to the transform routines are measured in iMCU blocks of the
72
* 6. All the routines assume that the source and destination buffers are
73
* padded out to a full iMCU boundary. This is true, although for the
74
* source buffer it is an undocumented property of jdcoefct.c.
79
do_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
80
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
81
jvirt_barray_ptr *src_coef_arrays,
82
jvirt_barray_ptr *dst_coef_arrays)
83
/* Crop. This is only used when no rotate/flip is requested with the crop. */
85
JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
87
JBLOCKARRAY src_buffer, dst_buffer;
88
jpeg_component_info *compptr;
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/* We simply have to copy the right amount of data (the destination's
91
* image size) starting at the given X and Y offsets in the source.
93
for (ci = 0; ci < dstinfo->num_components; ci++) {
94
compptr = dstinfo->comp_info + ci;
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x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
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y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
97
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
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dst_blk_y += compptr->v_samp_factor) {
99
dst_buffer = (*srcinfo->mem->access_virt_barray)
100
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
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(JDIMENSION) compptr->v_samp_factor, TRUE);
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src_buffer = (*srcinfo->mem->access_virt_barray)
103
((j_common_ptr) srcinfo, src_coef_arrays[ci],
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dst_blk_y + y_crop_blocks,
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(JDIMENSION) compptr->v_samp_factor, FALSE);
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for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
107
jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
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dst_buffer[offset_y],
109
compptr->width_in_blocks);
117
do_flip_h_no_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
118
JDIMENSION x_crop_offset,
119
jvirt_barray_ptr *src_coef_arrays)
120
/* Horizontal flip; done in-place, so no separate dest array is required.
121
* NB: this only works when y_crop_offset is zero.
124
JDIMENSION MCU_cols, comp_width, blk_x, blk_y, x_crop_blocks;
129
jpeg_component_info *compptr;
131
/* Horizontal mirroring of DCT blocks is accomplished by swapping
132
* pairs of blocks in-place. Within a DCT block, we perform horizontal
133
* mirroring by changing the signs of odd-numbered columns.
134
* Partial iMCUs at the right edge are left untouched.
136
MCU_cols = srcinfo->output_width /
137
(dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
139
for (ci = 0; ci < dstinfo->num_components; ci++) {
140
compptr = dstinfo->comp_info + ci;
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comp_width = MCU_cols * compptr->h_samp_factor;
142
x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
143
for (blk_y = 0; blk_y < compptr->height_in_blocks;
144
blk_y += compptr->v_samp_factor) {
145
buffer = (*srcinfo->mem->access_virt_barray)
146
((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
147
(JDIMENSION) compptr->v_samp_factor, TRUE);
148
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
149
/* Do the mirroring */
150
for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
151
ptr1 = buffer[offset_y][blk_x];
152
ptr2 = buffer[offset_y][comp_width - blk_x - 1];
153
/* this unrolled loop doesn't need to know which row it's on... */
154
for (k = 0; k < DCTSIZE2; k += 2) {
155
temp1 = *ptr1; /* swap even column */
159
temp1 = *ptr1; /* swap odd column with sign change */
165
if (x_crop_blocks > 0) {
166
/* Now left-justify the portion of the data to be kept.
167
* We can't use a single jcopy_block_row() call because that routine
168
* depends on memcpy(), whose behavior is unspecified for overlapping
169
* source and destination areas. Sigh.
171
for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
172
jcopy_block_row(buffer[offset_y] + blk_x + x_crop_blocks,
173
buffer[offset_y] + blk_x,
184
do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
185
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
186
jvirt_barray_ptr *src_coef_arrays,
187
jvirt_barray_ptr *dst_coef_arrays)
188
/* Horizontal flip in general cropping case */
190
JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
191
JDIMENSION x_crop_blocks, y_crop_blocks;
193
JBLOCKARRAY src_buffer, dst_buffer;
194
JBLOCKROW src_row_ptr, dst_row_ptr;
195
JCOEFPTR src_ptr, dst_ptr;
196
jpeg_component_info *compptr;
198
/* Here we must output into a separate array because we can't touch
199
* different rows of a single virtual array simultaneously. Otherwise,
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* this is essentially the same as the routine above.
202
MCU_cols = srcinfo->output_width /
203
(dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
205
for (ci = 0; ci < dstinfo->num_components; ci++) {
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compptr = dstinfo->comp_info + ci;
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comp_width = MCU_cols * compptr->h_samp_factor;
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x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
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y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
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for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
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dst_blk_y += compptr->v_samp_factor) {
212
dst_buffer = (*srcinfo->mem->access_virt_barray)
213
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
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(JDIMENSION) compptr->v_samp_factor, TRUE);
215
src_buffer = (*srcinfo->mem->access_virt_barray)
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((j_common_ptr) srcinfo, src_coef_arrays[ci],
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dst_blk_y + y_crop_blocks,
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(JDIMENSION) compptr->v_samp_factor, FALSE);
219
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
220
dst_row_ptr = dst_buffer[offset_y];
221
src_row_ptr = src_buffer[offset_y];
222
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
223
if (x_crop_blocks + dst_blk_x < comp_width) {
224
/* Do the mirrorable blocks */
225
dst_ptr = dst_row_ptr[dst_blk_x];
226
src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
227
/* this unrolled loop doesn't need to know which row it's on... */
228
for (k = 0; k < DCTSIZE2; k += 2) {
229
*dst_ptr++ = *src_ptr++; /* copy even column */
230
*dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */
233
/* Copy last partial block(s) verbatim */
234
jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
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dst_row_ptr + dst_blk_x,
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do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
247
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
248
jvirt_barray_ptr *src_coef_arrays,
249
jvirt_barray_ptr *dst_coef_arrays)
252
JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
253
JDIMENSION x_crop_blocks, y_crop_blocks;
254
int ci, i, j, offset_y;
255
JBLOCKARRAY src_buffer, dst_buffer;
256
JBLOCKROW src_row_ptr, dst_row_ptr;
257
JCOEFPTR src_ptr, dst_ptr;
258
jpeg_component_info *compptr;
260
/* We output into a separate array because we can't touch different
261
* rows of the source virtual array simultaneously. Otherwise, this
262
* is a pretty straightforward analog of horizontal flip.
263
* Within a DCT block, vertical mirroring is done by changing the signs
264
* of odd-numbered rows.
265
* Partial iMCUs at the bottom edge are copied verbatim.
267
MCU_rows = srcinfo->output_height /
268
(dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
270
for (ci = 0; ci < dstinfo->num_components; ci++) {
271
compptr = dstinfo->comp_info + ci;
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comp_height = MCU_rows * compptr->v_samp_factor;
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x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
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y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
275
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
276
dst_blk_y += compptr->v_samp_factor) {
277
dst_buffer = (*srcinfo->mem->access_virt_barray)
278
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
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(JDIMENSION) compptr->v_samp_factor, TRUE);
280
if (y_crop_blocks + dst_blk_y < comp_height) {
281
/* Row is within the mirrorable area. */
282
src_buffer = (*srcinfo->mem->access_virt_barray)
283
((j_common_ptr) srcinfo, src_coef_arrays[ci],
284
comp_height - y_crop_blocks - dst_blk_y -
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(JDIMENSION) compptr->v_samp_factor,
286
(JDIMENSION) compptr->v_samp_factor, FALSE);
288
/* Bottom-edge blocks will be copied verbatim. */
289
src_buffer = (*srcinfo->mem->access_virt_barray)
290
((j_common_ptr) srcinfo, src_coef_arrays[ci],
291
dst_blk_y + y_crop_blocks,
292
(JDIMENSION) compptr->v_samp_factor, FALSE);
294
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
295
if (y_crop_blocks + dst_blk_y < comp_height) {
296
/* Row is within the mirrorable area. */
297
dst_row_ptr = dst_buffer[offset_y];
298
src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
299
src_row_ptr += x_crop_blocks;
300
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
302
dst_ptr = dst_row_ptr[dst_blk_x];
303
src_ptr = src_row_ptr[dst_blk_x];
304
for (i = 0; i < DCTSIZE; i += 2) {
306
for (j = 0; j < DCTSIZE; j++)
307
*dst_ptr++ = *src_ptr++;
308
/* copy odd row with sign change */
309
for (j = 0; j < DCTSIZE; j++)
310
*dst_ptr++ = - *src_ptr++;
314
/* Just copy row verbatim. */
315
jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
316
dst_buffer[offset_y],
317
compptr->width_in_blocks);
326
do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
327
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
328
jvirt_barray_ptr *src_coef_arrays,
329
jvirt_barray_ptr *dst_coef_arrays)
330
/* Transpose source into destination */
332
JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
333
int ci, i, j, offset_x, offset_y;
334
JBLOCKARRAY src_buffer, dst_buffer;
335
JCOEFPTR src_ptr, dst_ptr;
336
jpeg_component_info *compptr;
338
/* Transposing pixels within a block just requires transposing the
340
* Partial iMCUs at the edges require no special treatment; we simply
341
* process all the available DCT blocks for every component.
343
for (ci = 0; ci < dstinfo->num_components; ci++) {
344
compptr = dstinfo->comp_info + ci;
345
x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
346
y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
347
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
348
dst_blk_y += compptr->v_samp_factor) {
349
dst_buffer = (*srcinfo->mem->access_virt_barray)
350
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
351
(JDIMENSION) compptr->v_samp_factor, TRUE);
352
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
353
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
354
dst_blk_x += compptr->h_samp_factor) {
355
src_buffer = (*srcinfo->mem->access_virt_barray)
356
((j_common_ptr) srcinfo, src_coef_arrays[ci],
357
dst_blk_x + x_crop_blocks,
358
(JDIMENSION) compptr->h_samp_factor, FALSE);
359
for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
360
dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
361
src_ptr = src_buffer[offset_x][dst_blk_y + offset_y + y_crop_blocks];
362
for (i = 0; i < DCTSIZE; i++)
363
for (j = 0; j < DCTSIZE; j++)
364
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
374
do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
375
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
376
jvirt_barray_ptr *src_coef_arrays,
377
jvirt_barray_ptr *dst_coef_arrays)
378
/* 90 degree rotation is equivalent to
379
* 1. Transposing the image;
380
* 2. Horizontal mirroring.
381
* These two steps are merged into a single processing routine.
384
JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
385
JDIMENSION x_crop_blocks, y_crop_blocks;
386
int ci, i, j, offset_x, offset_y;
387
JBLOCKARRAY src_buffer, dst_buffer;
388
JCOEFPTR src_ptr, dst_ptr;
389
jpeg_component_info *compptr;
391
/* Because of the horizontal mirror step, we can't process partial iMCUs
392
* at the (output) right edge properly. They just get transposed and
395
MCU_cols = srcinfo->output_height /
396
(dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
398
for (ci = 0; ci < dstinfo->num_components; ci++) {
399
compptr = dstinfo->comp_info + ci;
400
comp_width = MCU_cols * compptr->h_samp_factor;
401
x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
402
y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
403
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
404
dst_blk_y += compptr->v_samp_factor) {
405
dst_buffer = (*srcinfo->mem->access_virt_barray)
406
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
407
(JDIMENSION) compptr->v_samp_factor, TRUE);
408
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
409
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
410
dst_blk_x += compptr->h_samp_factor) {
411
if (x_crop_blocks + dst_blk_x < comp_width) {
412
/* Block is within the mirrorable area. */
413
src_buffer = (*srcinfo->mem->access_virt_barray)
414
((j_common_ptr) srcinfo, src_coef_arrays[ci],
415
comp_width - x_crop_blocks - dst_blk_x -
416
(JDIMENSION) compptr->h_samp_factor,
417
(JDIMENSION) compptr->h_samp_factor, FALSE);
419
/* Edge blocks are transposed but not mirrored. */
420
src_buffer = (*srcinfo->mem->access_virt_barray)
421
((j_common_ptr) srcinfo, src_coef_arrays[ci],
422
dst_blk_x + x_crop_blocks,
423
(JDIMENSION) compptr->h_samp_factor, FALSE);
425
for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
426
dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
427
if (x_crop_blocks + dst_blk_x < comp_width) {
428
/* Block is within the mirrorable area. */
429
src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
430
[dst_blk_y + offset_y + y_crop_blocks];
431
for (i = 0; i < DCTSIZE; i++) {
432
for (j = 0; j < DCTSIZE; j++)
433
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
435
for (j = 0; j < DCTSIZE; j++)
436
dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
439
/* Edge blocks are transposed but not mirrored. */
440
src_ptr = src_buffer[offset_x]
441
[dst_blk_y + offset_y + y_crop_blocks];
442
for (i = 0; i < DCTSIZE; i++)
443
for (j = 0; j < DCTSIZE; j++)
444
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
455
do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
456
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
457
jvirt_barray_ptr *src_coef_arrays,
458
jvirt_barray_ptr *dst_coef_arrays)
459
/* 270 degree rotation is equivalent to
460
* 1. Horizontal mirroring;
461
* 2. Transposing the image.
462
* These two steps are merged into a single processing routine.
465
JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
466
JDIMENSION x_crop_blocks, y_crop_blocks;
467
int ci, i, j, offset_x, offset_y;
468
JBLOCKARRAY src_buffer, dst_buffer;
469
JCOEFPTR src_ptr, dst_ptr;
470
jpeg_component_info *compptr;
472
/* Because of the horizontal mirror step, we can't process partial iMCUs
473
* at the (output) bottom edge properly. They just get transposed and
476
MCU_rows = srcinfo->output_width /
477
(dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
479
for (ci = 0; ci < dstinfo->num_components; ci++) {
480
compptr = dstinfo->comp_info + ci;
481
comp_height = MCU_rows * compptr->v_samp_factor;
482
x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
483
y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
484
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
485
dst_blk_y += compptr->v_samp_factor) {
486
dst_buffer = (*srcinfo->mem->access_virt_barray)
487
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
488
(JDIMENSION) compptr->v_samp_factor, TRUE);
489
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
490
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
491
dst_blk_x += compptr->h_samp_factor) {
492
src_buffer = (*srcinfo->mem->access_virt_barray)
493
((j_common_ptr) srcinfo, src_coef_arrays[ci],
494
dst_blk_x + x_crop_blocks,
495
(JDIMENSION) compptr->h_samp_factor, FALSE);
496
for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
497
dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
498
if (y_crop_blocks + dst_blk_y < comp_height) {
499
/* Block is within the mirrorable area. */
500
src_ptr = src_buffer[offset_x]
501
[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
502
for (i = 0; i < DCTSIZE; i++) {
503
for (j = 0; j < DCTSIZE; j++) {
504
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
506
dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
510
/* Edge blocks are transposed but not mirrored. */
511
src_ptr = src_buffer[offset_x]
512
[dst_blk_y + offset_y + y_crop_blocks];
513
for (i = 0; i < DCTSIZE; i++)
514
for (j = 0; j < DCTSIZE; j++)
515
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
526
do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
527
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
528
jvirt_barray_ptr *src_coef_arrays,
529
jvirt_barray_ptr *dst_coef_arrays)
530
/* 180 degree rotation is equivalent to
531
* 1. Vertical mirroring;
532
* 2. Horizontal mirroring.
533
* These two steps are merged into a single processing routine.
536
JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
537
JDIMENSION x_crop_blocks, y_crop_blocks;
538
int ci, i, j, offset_y;
539
JBLOCKARRAY src_buffer, dst_buffer;
540
JBLOCKROW src_row_ptr, dst_row_ptr;
541
JCOEFPTR src_ptr, dst_ptr;
542
jpeg_component_info *compptr;
544
MCU_cols = srcinfo->output_width /
545
(dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
546
MCU_rows = srcinfo->output_height /
547
(dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
549
for (ci = 0; ci < dstinfo->num_components; ci++) {
550
compptr = dstinfo->comp_info + ci;
551
comp_width = MCU_cols * compptr->h_samp_factor;
552
comp_height = MCU_rows * compptr->v_samp_factor;
553
x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
554
y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
555
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
556
dst_blk_y += compptr->v_samp_factor) {
557
dst_buffer = (*srcinfo->mem->access_virt_barray)
558
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
559
(JDIMENSION) compptr->v_samp_factor, TRUE);
560
if (y_crop_blocks + dst_blk_y < comp_height) {
561
/* Row is within the vertically mirrorable area. */
562
src_buffer = (*srcinfo->mem->access_virt_barray)
563
((j_common_ptr) srcinfo, src_coef_arrays[ci],
564
comp_height - y_crop_blocks - dst_blk_y -
565
(JDIMENSION) compptr->v_samp_factor,
566
(JDIMENSION) compptr->v_samp_factor, FALSE);
568
/* Bottom-edge rows are only mirrored horizontally. */
569
src_buffer = (*srcinfo->mem->access_virt_barray)
570
((j_common_ptr) srcinfo, src_coef_arrays[ci],
571
dst_blk_y + y_crop_blocks,
572
(JDIMENSION) compptr->v_samp_factor, FALSE);
574
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
575
dst_row_ptr = dst_buffer[offset_y];
576
if (y_crop_blocks + dst_blk_y < comp_height) {
577
/* Row is within the mirrorable area. */
578
src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
579
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
580
dst_ptr = dst_row_ptr[dst_blk_x];
581
if (x_crop_blocks + dst_blk_x < comp_width) {
582
/* Process the blocks that can be mirrored both ways. */
583
src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
584
for (i = 0; i < DCTSIZE; i += 2) {
585
/* For even row, negate every odd column. */
586
for (j = 0; j < DCTSIZE; j += 2) {
587
*dst_ptr++ = *src_ptr++;
588
*dst_ptr++ = - *src_ptr++;
590
/* For odd row, negate every even column. */
591
for (j = 0; j < DCTSIZE; j += 2) {
592
*dst_ptr++ = - *src_ptr++;
593
*dst_ptr++ = *src_ptr++;
597
/* Any remaining right-edge blocks are only mirrored vertically. */
598
src_ptr = src_row_ptr[x_crop_blocks + dst_blk_x];
599
for (i = 0; i < DCTSIZE; i += 2) {
600
for (j = 0; j < DCTSIZE; j++)
601
*dst_ptr++ = *src_ptr++;
602
for (j = 0; j < DCTSIZE; j++)
603
*dst_ptr++ = - *src_ptr++;
608
/* Remaining rows are just mirrored horizontally. */
609
src_row_ptr = src_buffer[offset_y];
610
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
611
if (x_crop_blocks + dst_blk_x < comp_width) {
612
/* Process the blocks that can be mirrored. */
613
dst_ptr = dst_row_ptr[dst_blk_x];
614
src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];
615
for (i = 0; i < DCTSIZE2; i += 2) {
616
*dst_ptr++ = *src_ptr++;
617
*dst_ptr++ = - *src_ptr++;
620
/* Any remaining right-edge blocks are only copied. */
621
jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,
622
dst_row_ptr + dst_blk_x,
634
do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
635
JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
636
jvirt_barray_ptr *src_coef_arrays,
637
jvirt_barray_ptr *dst_coef_arrays)
638
/* Transverse transpose is equivalent to
639
* 1. 180 degree rotation;
642
* 1. Horizontal mirroring;
644
* 3. Horizontal mirroring.
645
* These steps are merged into a single processing routine.
648
JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
649
JDIMENSION x_crop_blocks, y_crop_blocks;
650
int ci, i, j, offset_x, offset_y;
651
JBLOCKARRAY src_buffer, dst_buffer;
652
JCOEFPTR src_ptr, dst_ptr;
653
jpeg_component_info *compptr;
655
MCU_cols = srcinfo->output_height /
656
(dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
657
MCU_rows = srcinfo->output_width /
658
(dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
660
for (ci = 0; ci < dstinfo->num_components; ci++) {
661
compptr = dstinfo->comp_info + ci;
662
comp_width = MCU_cols * compptr->h_samp_factor;
663
comp_height = MCU_rows * compptr->v_samp_factor;
664
x_crop_blocks = x_crop_offset * compptr->h_samp_factor;
665
y_crop_blocks = y_crop_offset * compptr->v_samp_factor;
666
for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
667
dst_blk_y += compptr->v_samp_factor) {
668
dst_buffer = (*srcinfo->mem->access_virt_barray)
669
((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
670
(JDIMENSION) compptr->v_samp_factor, TRUE);
671
for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
672
for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
673
dst_blk_x += compptr->h_samp_factor) {
674
if (x_crop_blocks + dst_blk_x < comp_width) {
675
/* Block is within the mirrorable area. */
676
src_buffer = (*srcinfo->mem->access_virt_barray)
677
((j_common_ptr) srcinfo, src_coef_arrays[ci],
678
comp_width - x_crop_blocks - dst_blk_x -
679
(JDIMENSION) compptr->h_samp_factor,
680
(JDIMENSION) compptr->h_samp_factor, FALSE);
682
src_buffer = (*srcinfo->mem->access_virt_barray)
683
((j_common_ptr) srcinfo, src_coef_arrays[ci],
684
dst_blk_x + x_crop_blocks,
685
(JDIMENSION) compptr->h_samp_factor, FALSE);
687
for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
688
dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
689
if (y_crop_blocks + dst_blk_y < comp_height) {
690
if (x_crop_blocks + dst_blk_x < comp_width) {
691
/* Block is within the mirrorable area. */
692
src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
693
[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
694
for (i = 0; i < DCTSIZE; i++) {
695
for (j = 0; j < DCTSIZE; j++) {
696
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
698
dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
701
for (j = 0; j < DCTSIZE; j++) {
702
dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
704
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
708
/* Right-edge blocks are mirrored in y only */
709
src_ptr = src_buffer[offset_x]
710
[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];
711
for (i = 0; i < DCTSIZE; i++) {
712
for (j = 0; j < DCTSIZE; j++) {
713
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
715
dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
720
if (x_crop_blocks + dst_blk_x < comp_width) {
721
/* Bottom-edge blocks are mirrored in x only */
722
src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]
723
[dst_blk_y + offset_y + y_crop_blocks];
724
for (i = 0; i < DCTSIZE; i++) {
725
for (j = 0; j < DCTSIZE; j++)
726
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
728
for (j = 0; j < DCTSIZE; j++)
729
dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
732
/* At lower right corner, just transpose, no mirroring */
733
src_ptr = src_buffer[offset_x]
734
[dst_blk_y + offset_y + y_crop_blocks];
735
for (i = 0; i < DCTSIZE; i++)
736
for (j = 0; j < DCTSIZE; j++)
737
dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
748
/* Parse an unsigned integer: subroutine for jtransform_parse_crop_spec.
749
* Returns TRUE if valid integer found, FALSE if not.
750
* *strptr is advanced over the digit string, and *result is set to its value.
754
jt_read_integer (const char ** strptr, JDIMENSION * result)
756
const char * ptr = *strptr;
759
for (; isdigit(*ptr); ptr++) {
760
val = val * 10 + (JDIMENSION) (*ptr - '0');
764
return FALSE; /* oops, no digits */
770
/* Parse a crop specification (written in X11 geometry style).
771
* The routine returns TRUE if the spec string is valid, FALSE if not.
773
* The crop spec string should have the format
774
* <width>x<height>{+-}<xoffset>{+-}<yoffset>
775
* where width, height, xoffset, and yoffset are unsigned integers.
776
* Each of the elements can be omitted to indicate a default value.
777
* (A weakness of this style is that it is not possible to omit xoffset
778
* while specifying yoffset, since they look alike.)
780
* This code is loosely based on XParseGeometry from the X11 distribution.
784
jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)
787
info->crop_width_set = JCROP_UNSET;
788
info->crop_height_set = JCROP_UNSET;
789
info->crop_xoffset_set = JCROP_UNSET;
790
info->crop_yoffset_set = JCROP_UNSET;
792
if (isdigit(*spec)) {
794
if (! jt_read_integer(&spec, &info->crop_width))
796
info->crop_width_set = JCROP_POS;
798
if (*spec == 'x' || *spec == 'X') {
801
if (! jt_read_integer(&spec, &info->crop_height))
803
info->crop_height_set = JCROP_POS;
805
if (*spec == '+' || *spec == '-') {
807
info->crop_xoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
809
if (! jt_read_integer(&spec, &info->crop_xoffset))
812
if (*spec == '+' || *spec == '-') {
814
info->crop_yoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;
816
if (! jt_read_integer(&spec, &info->crop_yoffset))
819
/* We had better have gotten to the end of the string. */
827
/* Trim off any partial iMCUs on the indicated destination edge */
830
trim_right_edge (jpeg_transform_info *info, JDIMENSION full_width)
834
MCU_cols = info->output_width / info->iMCU_sample_width;
835
if (MCU_cols > 0 && info->x_crop_offset + MCU_cols ==
836
full_width / info->iMCU_sample_width)
837
info->output_width = MCU_cols * info->iMCU_sample_width;
841
trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height)
845
MCU_rows = info->output_height / info->iMCU_sample_height;
846
if (MCU_rows > 0 && info->y_crop_offset + MCU_rows ==
847
full_height / info->iMCU_sample_height)
848
info->output_height = MCU_rows * info->iMCU_sample_height;
852
/* Request any required workspace.
854
* This routine figures out the size that the output image will be
855
* (which implies that all the transform parameters must be set before
858
* We allocate the workspace virtual arrays from the source decompression
859
* object, so that all the arrays (both the original data and the workspace)
860
* will be taken into account while making memory management decisions.
861
* Hence, this routine must be called after jpeg_read_header (which reads
862
* the image dimensions) and before jpeg_read_coefficients (which realizes
863
* the source's virtual arrays).
865
* This function returns FALSE right away if -perfect is given
866
* and transformation is not perfect. Otherwise returns TRUE.
870
jtransform_request_workspace (j_decompress_ptr srcinfo,
871
jpeg_transform_info *info)
873
jvirt_barray_ptr *coef_arrays;
874
boolean need_workspace, transpose_it;
875
jpeg_component_info *compptr;
876
JDIMENSION xoffset, yoffset;
877
JDIMENSION width_in_iMCUs, height_in_iMCUs;
878
JDIMENSION width_in_blocks, height_in_blocks;
879
int ci, h_samp_factor, v_samp_factor;
881
/* Determine number of components in output image */
882
if (info->force_grayscale &&
883
srcinfo->jpeg_color_space == JCS_YCbCr &&
884
srcinfo->num_components == 3)
885
/* We'll only process the first component */
886
info->num_components = 1;
888
/* Process all the components */
889
info->num_components = srcinfo->num_components;
891
/* Compute output image dimensions and related values. */
892
jpeg_core_output_dimensions(srcinfo);
894
/* Return right away if -perfect is given and transformation is not perfect.
897
if (info->num_components == 1) {
898
if (!jtransform_perfect_transform(srcinfo->output_width,
899
srcinfo->output_height,
900
srcinfo->min_DCT_h_scaled_size,
901
srcinfo->min_DCT_v_scaled_size,
905
if (!jtransform_perfect_transform(srcinfo->output_width,
906
srcinfo->output_height,
907
srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size,
908
srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size,
914
/* If there is only one output component, force the iMCU size to be 1;
915
* else use the source iMCU size. (This allows us to do the right thing
916
* when reducing color to grayscale, and also provides a handy way of
917
* cleaning up "funny" grayscale images whose sampling factors are not 1x1.)
919
switch (info->transform) {
920
case JXFORM_TRANSPOSE:
921
case JXFORM_TRANSVERSE:
924
info->output_width = srcinfo->output_height;
925
info->output_height = srcinfo->output_width;
926
if (info->num_components == 1) {
927
info->iMCU_sample_width = srcinfo->min_DCT_v_scaled_size;
928
info->iMCU_sample_height = srcinfo->min_DCT_h_scaled_size;
930
info->iMCU_sample_width =
931
srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
932
info->iMCU_sample_height =
933
srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
937
info->output_width = srcinfo->output_width;
938
info->output_height = srcinfo->output_height;
939
if (info->num_components == 1) {
940
info->iMCU_sample_width = srcinfo->min_DCT_h_scaled_size;
941
info->iMCU_sample_height = srcinfo->min_DCT_v_scaled_size;
943
info->iMCU_sample_width =
944
srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
945
info->iMCU_sample_height =
946
srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
951
/* If cropping has been requested, compute the crop area's position and
952
* dimensions, ensuring that its upper left corner falls at an iMCU boundary.
955
/* Insert default values for unset crop parameters */
956
if (info->crop_xoffset_set == JCROP_UNSET)
957
info->crop_xoffset = 0; /* default to +0 */
958
if (info->crop_yoffset_set == JCROP_UNSET)
959
info->crop_yoffset = 0; /* default to +0 */
960
if (info->crop_xoffset >= info->output_width ||
961
info->crop_yoffset >= info->output_height)
962
ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
963
if (info->crop_width_set == JCROP_UNSET)
964
info->crop_width = info->output_width - info->crop_xoffset;
965
if (info->crop_height_set == JCROP_UNSET)
966
info->crop_height = info->output_height - info->crop_yoffset;
967
/* Ensure parameters are valid */
968
if (info->crop_width <= 0 || info->crop_width > info->output_width ||
969
info->crop_height <= 0 || info->crop_height > info->output_height ||
970
info->crop_xoffset > info->output_width - info->crop_width ||
971
info->crop_yoffset > info->output_height - info->crop_height)
972
ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
973
/* Convert negative crop offsets into regular offsets */
974
if (info->crop_xoffset_set == JCROP_NEG)
975
xoffset = info->output_width - info->crop_width - info->crop_xoffset;
977
xoffset = info->crop_xoffset;
978
if (info->crop_yoffset_set == JCROP_NEG)
979
yoffset = info->output_height - info->crop_height - info->crop_yoffset;
981
yoffset = info->crop_yoffset;
982
/* Now adjust so that upper left corner falls at an iMCU boundary */
984
info->crop_width + (xoffset % info->iMCU_sample_width);
985
info->output_height =
986
info->crop_height + (yoffset % info->iMCU_sample_height);
987
/* Save x/y offsets measured in iMCUs */
988
info->x_crop_offset = xoffset / info->iMCU_sample_width;
989
info->y_crop_offset = yoffset / info->iMCU_sample_height;
991
info->x_crop_offset = 0;
992
info->y_crop_offset = 0;
995
/* Figure out whether we need workspace arrays,
996
* and if so whether they are transposed relative to the source.
998
need_workspace = FALSE;
999
transpose_it = FALSE;
1000
switch (info->transform) {
1002
if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
1003
need_workspace = TRUE;
1004
/* No workspace needed if neither cropping nor transforming */
1008
trim_right_edge(info, srcinfo->output_width);
1009
if (info->y_crop_offset != 0)
1010
need_workspace = TRUE;
1011
/* do_flip_h_no_crop doesn't need a workspace array */
1015
trim_bottom_edge(info, srcinfo->output_height);
1016
/* Need workspace arrays having same dimensions as source image. */
1017
need_workspace = TRUE;
1019
case JXFORM_TRANSPOSE:
1020
/* transpose does NOT have to trim anything */
1021
/* Need workspace arrays having transposed dimensions. */
1022
need_workspace = TRUE;
1023
transpose_it = TRUE;
1025
case JXFORM_TRANSVERSE:
1027
trim_right_edge(info, srcinfo->output_height);
1028
trim_bottom_edge(info, srcinfo->output_width);
1030
/* Need workspace arrays having transposed dimensions. */
1031
need_workspace = TRUE;
1032
transpose_it = TRUE;
1036
trim_right_edge(info, srcinfo->output_height);
1037
/* Need workspace arrays having transposed dimensions. */
1038
need_workspace = TRUE;
1039
transpose_it = TRUE;
1041
case JXFORM_ROT_180:
1043
trim_right_edge(info, srcinfo->output_width);
1044
trim_bottom_edge(info, srcinfo->output_height);
1046
/* Need workspace arrays having same dimensions as source image. */
1047
need_workspace = TRUE;
1049
case JXFORM_ROT_270:
1051
trim_bottom_edge(info, srcinfo->output_width);
1052
/* Need workspace arrays having transposed dimensions. */
1053
need_workspace = TRUE;
1054
transpose_it = TRUE;
1058
/* Allocate workspace if needed.
1059
* Note that we allocate arrays padded out to the next iMCU boundary,
1060
* so that transform routines need not worry about missing edge blocks.
1062
if (need_workspace) {
1063
coef_arrays = (jvirt_barray_ptr *)
1064
(*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
1065
SIZEOF(jvirt_barray_ptr) * info->num_components);
1066
width_in_iMCUs = (JDIMENSION)
1067
jdiv_round_up((long) info->output_width,
1068
(long) info->iMCU_sample_width);
1069
height_in_iMCUs = (JDIMENSION)
1070
jdiv_round_up((long) info->output_height,
1071
(long) info->iMCU_sample_height);
1072
for (ci = 0; ci < info->num_components; ci++) {
1073
compptr = srcinfo->comp_info + ci;
1074
if (info->num_components == 1) {
1075
/* we're going to force samp factors to 1x1 in this case */
1076
h_samp_factor = v_samp_factor = 1;
1077
} else if (transpose_it) {
1078
h_samp_factor = compptr->v_samp_factor;
1079
v_samp_factor = compptr->h_samp_factor;
1081
h_samp_factor = compptr->h_samp_factor;
1082
v_samp_factor = compptr->v_samp_factor;
1084
width_in_blocks = width_in_iMCUs * h_samp_factor;
1085
height_in_blocks = height_in_iMCUs * v_samp_factor;
1086
coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
1087
((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
1088
width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);
1090
info->workspace_coef_arrays = coef_arrays;
1092
info->workspace_coef_arrays = NULL;
1098
/* Transpose destination image parameters */
1101
transpose_critical_parameters (j_compress_ptr dstinfo)
1103
int tblno, i, j, ci, itemp;
1104
jpeg_component_info *compptr;
1105
JQUANT_TBL *qtblptr;
1109
/* Transpose image dimensions */
1110
jtemp = dstinfo->image_width;
1111
dstinfo->image_width = dstinfo->image_height;
1112
dstinfo->image_height = jtemp;
1113
itemp = dstinfo->min_DCT_h_scaled_size;
1114
dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;
1115
dstinfo->min_DCT_v_scaled_size = itemp;
1117
/* Transpose sampling factors */
1118
for (ci = 0; ci < dstinfo->num_components; ci++) {
1119
compptr = dstinfo->comp_info + ci;
1120
itemp = compptr->h_samp_factor;
1121
compptr->h_samp_factor = compptr->v_samp_factor;
1122
compptr->v_samp_factor = itemp;
1125
/* Transpose quantization tables */
1126
for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
1127
qtblptr = dstinfo->quant_tbl_ptrs[tblno];
1128
if (qtblptr != NULL) {
1129
for (i = 0; i < DCTSIZE; i++) {
1130
for (j = 0; j < i; j++) {
1131
qtemp = qtblptr->quantval[i*DCTSIZE+j];
1132
qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
1133
qtblptr->quantval[j*DCTSIZE+i] = qtemp;
1141
/* Adjust Exif image parameters.
1143
* We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.
1147
adjust_exif_parameters (JOCTET FAR * data, unsigned int length,
1148
JDIMENSION new_width, JDIMENSION new_height)
1150
boolean is_motorola; /* Flag for byte order */
1151
unsigned int number_of_tags, tagnum;
1152
unsigned int firstoffset, offset;
1153
JDIMENSION new_value;
1155
if (length < 12) return; /* Length of an IFD entry */
1157
/* Discover byte order */
1158
if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)
1159
is_motorola = FALSE;
1160
else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)
1165
/* Check Tag Mark */
1167
if (GETJOCTET(data[2]) != 0) return;
1168
if (GETJOCTET(data[3]) != 0x2A) return;
1170
if (GETJOCTET(data[3]) != 0) return;
1171
if (GETJOCTET(data[2]) != 0x2A) return;
1174
/* Get first IFD offset (offset to IFD0) */
1176
if (GETJOCTET(data[4]) != 0) return;
1177
if (GETJOCTET(data[5]) != 0) return;
1178
firstoffset = GETJOCTET(data[6]);
1180
firstoffset += GETJOCTET(data[7]);
1182
if (GETJOCTET(data[7]) != 0) return;
1183
if (GETJOCTET(data[6]) != 0) return;
1184
firstoffset = GETJOCTET(data[5]);
1186
firstoffset += GETJOCTET(data[4]);
1188
if (firstoffset > length - 2) return; /* check end of data segment */
1190
/* Get the number of directory entries contained in this IFD */
1192
number_of_tags = GETJOCTET(data[firstoffset]);
1193
number_of_tags <<= 8;
1194
number_of_tags += GETJOCTET(data[firstoffset+1]);
1196
number_of_tags = GETJOCTET(data[firstoffset+1]);
1197
number_of_tags <<= 8;
1198
number_of_tags += GETJOCTET(data[firstoffset]);
1200
if (number_of_tags == 0) return;
1203
/* Search for ExifSubIFD offset Tag in IFD0 */
1205
if (firstoffset > length - 12) return; /* check end of data segment */
1206
/* Get Tag number */
1208
tagnum = GETJOCTET(data[firstoffset]);
1210
tagnum += GETJOCTET(data[firstoffset+1]);
1212
tagnum = GETJOCTET(data[firstoffset+1]);
1214
tagnum += GETJOCTET(data[firstoffset]);
1216
if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */
1217
if (--number_of_tags == 0) return;
1221
/* Get the ExifSubIFD offset */
1223
if (GETJOCTET(data[firstoffset+8]) != 0) return;
1224
if (GETJOCTET(data[firstoffset+9]) != 0) return;
1225
offset = GETJOCTET(data[firstoffset+10]);
1227
offset += GETJOCTET(data[firstoffset+11]);
1229
if (GETJOCTET(data[firstoffset+11]) != 0) return;
1230
if (GETJOCTET(data[firstoffset+10]) != 0) return;
1231
offset = GETJOCTET(data[firstoffset+9]);
1233
offset += GETJOCTET(data[firstoffset+8]);
1235
if (offset > length - 2) return; /* check end of data segment */
1237
/* Get the number of directory entries contained in this SubIFD */
1239
number_of_tags = GETJOCTET(data[offset]);
1240
number_of_tags <<= 8;
1241
number_of_tags += GETJOCTET(data[offset+1]);
1243
number_of_tags = GETJOCTET(data[offset+1]);
1244
number_of_tags <<= 8;
1245
number_of_tags += GETJOCTET(data[offset]);
1247
if (number_of_tags < 2) return;
1250
/* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */
1252
if (offset > length - 12) return; /* check end of data segment */
1253
/* Get Tag number */
1255
tagnum = GETJOCTET(data[offset]);
1257
tagnum += GETJOCTET(data[offset+1]);
1259
tagnum = GETJOCTET(data[offset+1]);
1261
tagnum += GETJOCTET(data[offset]);
1263
if (tagnum == 0xA002 || tagnum == 0xA003) {
1264
if (tagnum == 0xA002)
1265
new_value = new_width; /* ExifImageWidth Tag */
1267
new_value = new_height; /* ExifImageHeight Tag */
1269
data[offset+2] = 0; /* Format = unsigned long (4 octets) */
1271
data[offset+4] = 0; /* Number Of Components = 1 */
1277
data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);
1278
data[offset+11] = (JOCTET)(new_value & 0xFF);
1280
data[offset+2] = 4; /* Format = unsigned long (4 octets) */
1282
data[offset+4] = 1; /* Number Of Components = 1 */
1286
data[offset+8] = (JOCTET)(new_value & 0xFF);
1287
data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);
1288
data[offset+10] = 0;
1289
data[offset+11] = 0;
1293
} while (--number_of_tags);
1297
/* Adjust output image parameters as needed.
1299
* This must be called after jpeg_copy_critical_parameters()
1300
* and before jpeg_write_coefficients().
1302
* The return value is the set of virtual coefficient arrays to be written
1303
* (either the ones allocated by jtransform_request_workspace, or the
1304
* original source data arrays). The caller will need to pass this value
1305
* to jpeg_write_coefficients().
1308
GLOBAL(jvirt_barray_ptr *)
1309
jtransform_adjust_parameters (j_decompress_ptr srcinfo,
1310
j_compress_ptr dstinfo,
1311
jvirt_barray_ptr *src_coef_arrays,
1312
jpeg_transform_info *info)
1314
/* If force-to-grayscale is requested, adjust destination parameters */
1315
if (info->force_grayscale) {
1316
/* First, ensure we have YCbCr or grayscale data, and that the source's
1317
* Y channel is full resolution. (No reasonable person would make Y
1318
* be less than full resolution, so actually coping with that case
1319
* isn't worth extra code space. But we check it to avoid crashing.)
1321
if (((dstinfo->jpeg_color_space == JCS_YCbCr &&
1322
dstinfo->num_components == 3) ||
1323
(dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
1324
dstinfo->num_components == 1)) &&
1325
srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&
1326
srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {
1327
/* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
1328
* properly. Among other things, it sets the target h_samp_factor &
1329
* v_samp_factor to 1, which typically won't match the source.
1330
* We have to preserve the source's quantization table number, however.
1332
int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
1333
jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
1334
dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
1336
/* Sorry, can't do it */
1337
ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
1339
} else if (info->num_components == 1) {
1340
/* For a single-component source, we force the destination sampling factors
1341
* to 1x1, with or without force_grayscale. This is useful because some
1342
* decoders choke on grayscale images with other sampling factors.
1344
dstinfo->comp_info[0].h_samp_factor = 1;
1345
dstinfo->comp_info[0].v_samp_factor = 1;
1348
/* Correct the destination's image dimensions as necessary
1349
* for rotate/flip, resize, and crop operations.
1351
dstinfo->jpeg_width = info->output_width;
1352
dstinfo->jpeg_height = info->output_height;
1354
/* Transpose destination image parameters */
1355
switch (info->transform) {
1356
case JXFORM_TRANSPOSE:
1357
case JXFORM_TRANSVERSE:
1359
case JXFORM_ROT_270:
1360
transpose_critical_parameters(dstinfo);
1366
/* Adjust Exif properties */
1367
if (srcinfo->marker_list != NULL &&
1368
srcinfo->marker_list->marker == JPEG_APP0+1 &&
1369
srcinfo->marker_list->data_length >= 6 &&
1370
GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&
1371
GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&
1372
GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&
1373
GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&
1374
GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&
1375
GETJOCTET(srcinfo->marker_list->data[5]) == 0) {
1376
/* Suppress output of JFIF marker */
1377
dstinfo->write_JFIF_header = FALSE;
1378
/* Adjust Exif image parameters */
1379
if (dstinfo->jpeg_width != srcinfo->image_width ||
1380
dstinfo->jpeg_height != srcinfo->image_height)
1381
/* Align data segment to start of TIFF structure for parsing */
1382
adjust_exif_parameters(srcinfo->marker_list->data + 6,
1383
srcinfo->marker_list->data_length - 6,
1384
dstinfo->jpeg_width, dstinfo->jpeg_height);
1387
/* Return the appropriate output data set */
1388
if (info->workspace_coef_arrays != NULL)
1389
return info->workspace_coef_arrays;
1390
return src_coef_arrays;
1394
/* Execute the actual transformation, if any.
1396
* This must be called *after* jpeg_write_coefficients, because it depends
1397
* on jpeg_write_coefficients to have computed subsidiary values such as
1398
* the per-component width and height fields in the destination object.
1400
* Note that some transformations will modify the source data arrays!
1404
jtransform_execute_transform (j_decompress_ptr srcinfo,
1405
j_compress_ptr dstinfo,
1406
jvirt_barray_ptr *src_coef_arrays,
1407
jpeg_transform_info *info)
1409
jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
1411
/* Note: conditions tested here should match those in switch statement
1412
* in jtransform_request_workspace()
1414
switch (info->transform) {
1416
if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
1417
do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1418
src_coef_arrays, dst_coef_arrays);
1421
if (info->y_crop_offset != 0)
1422
do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1423
src_coef_arrays, dst_coef_arrays);
1425
do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,
1429
do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1430
src_coef_arrays, dst_coef_arrays);
1432
case JXFORM_TRANSPOSE:
1433
do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1434
src_coef_arrays, dst_coef_arrays);
1436
case JXFORM_TRANSVERSE:
1437
do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1438
src_coef_arrays, dst_coef_arrays);
1441
do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1442
src_coef_arrays, dst_coef_arrays);
1444
case JXFORM_ROT_180:
1445
do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1446
src_coef_arrays, dst_coef_arrays);
1448
case JXFORM_ROT_270:
1449
do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
1450
src_coef_arrays, dst_coef_arrays);
1455
/* jtransform_perfect_transform
1457
* Determine whether lossless transformation is perfectly
1458
* possible for a specified image and transformation.
1461
* image_width, image_height: source image dimensions.
1462
* MCU_width, MCU_height: pixel dimensions of MCU.
1463
* transform: transformation identifier.
1464
* Parameter sources from initialized jpeg_struct
1465
* (after reading source header):
1466
* image_width = cinfo.image_width
1467
* image_height = cinfo.image_height
1468
* MCU_width = cinfo.max_h_samp_factor * cinfo.block_size
1469
* MCU_height = cinfo.max_v_samp_factor * cinfo.block_size
1471
* TRUE = perfect transformation possible
1472
* FALSE = perfect transformation not possible
1473
* (may use custom action then)
1477
jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,
1478
int MCU_width, int MCU_height,
1479
JXFORM_CODE transform)
1481
boolean result = TRUE; /* initialize TRUE */
1483
switch (transform) {
1485
case JXFORM_ROT_270:
1486
if (image_width % (JDIMENSION) MCU_width)
1491
if (image_height % (JDIMENSION) MCU_height)
1494
case JXFORM_TRANSVERSE:
1495
case JXFORM_ROT_180:
1496
if (image_width % (JDIMENSION) MCU_width)
1498
if (image_height % (JDIMENSION) MCU_height)
1508
#endif /* TRANSFORMS_SUPPORTED */
1511
/* Setup decompression object to save desired markers in memory.
1512
* This must be called before jpeg_read_header() to have the desired effect.
1516
jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
1518
#ifdef SAVE_MARKERS_SUPPORTED
1521
/* Save comments except under NONE option */
1522
if (option != JCOPYOPT_NONE) {
1523
jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
1525
/* Save all types of APPn markers iff ALL option */
1526
if (option == JCOPYOPT_ALL) {
1527
for (m = 0; m < 16; m++)
1528
jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
1530
#endif /* SAVE_MARKERS_SUPPORTED */
1533
/* Copy markers saved in the given source object to the destination object.
1534
* This should be called just after jpeg_start_compress() or
1535
* jpeg_write_coefficients().
1536
* Note that those routines will have written the SOI, and also the
1537
* JFIF APP0 or Adobe APP14 markers if selected.
1541
jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
1542
JCOPY_OPTION option)
1544
jpeg_saved_marker_ptr marker;
1546
/* In the current implementation, we don't actually need to examine the
1547
* option flag here; we just copy everything that got saved.
1548
* But to avoid confusion, we do not output JFIF and Adobe APP14 markers
1549
* if the encoder library already wrote one.
1551
for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
1552
if (dstinfo->write_JFIF_header &&
1553
marker->marker == JPEG_APP0 &&
1554
marker->data_length >= 5 &&
1555
GETJOCTET(marker->data[0]) == 0x4A &&
1556
GETJOCTET(marker->data[1]) == 0x46 &&
1557
GETJOCTET(marker->data[2]) == 0x49 &&
1558
GETJOCTET(marker->data[3]) == 0x46 &&
1559
GETJOCTET(marker->data[4]) == 0)
1560
continue; /* reject duplicate JFIF */
1561
if (dstinfo->write_Adobe_marker &&
1562
marker->marker == JPEG_APP0+14 &&
1563
marker->data_length >= 5 &&
1564
GETJOCTET(marker->data[0]) == 0x41 &&
1565
GETJOCTET(marker->data[1]) == 0x64 &&
1566
GETJOCTET(marker->data[2]) == 0x6F &&
1567
GETJOCTET(marker->data[3]) == 0x62 &&
1568
GETJOCTET(marker->data[4]) == 0x65)
1569
continue; /* reject duplicate Adobe */
1570
#ifdef NEED_FAR_POINTERS
1571
/* We could use jpeg_write_marker if the data weren't FAR... */
1574
jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
1575
for (i = 0; i < marker->data_length; i++)
1576
jpeg_write_m_byte(dstinfo, marker->data[i]);
1579
jpeg_write_marker(dstinfo, marker->marker,
1580
marker->data, marker->data_length);
added
removed
source/Irrlicht/jpeglib/transupp.c
