Doxygen Source Code Documentation
jcsample.c File Reference
#include "jinclude.h"#include "jpeglib.h"Go to the source code of this file.
Define Documentation
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Definition at line 48 of file jcsample.c. |
Typedef Documentation
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Definition at line 67 of file jcsample.c. |
Function Documentation
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Definition at line 87 of file jcsample.c. References JDIMENSION, JSAMPARRAY, JSAMPLE, JSAMPROW, num_rows, and pixval. Referenced by fullsize_downsample(), fullsize_smooth_downsample(), h2v1_downsample(), h2v2_downsample(), h2v2_smooth_downsample(), and int_downsample().
00089 {
00090 register JSAMPROW ptr;
00091 register JSAMPLE pixval;
00092 register int count;
00093 int row;
00094 int numcols = (int) (output_cols - input_cols);
00095
00096 if (numcols > 0) {
00097 for (row = 0; row < num_rows; row++) {
00098 ptr = image_data[row] + input_cols;
00099 pixval = ptr[-1]; /* don't need GETJSAMPLE() here */
00100 for (count = numcols; count > 0; count--)
00101 *ptr++ = pixval;
00102 }
00103 }
00104 }
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Definition at line 187 of file jcsample.c. References compptr, expand_right_edge(), jpeg_compress_struct::image_width, jcopy_sample_rows(), JSAMPARRAY, jpeg_compress_struct::max_v_samp_factor, and jpeg_component_info::width_in_blocks. Referenced by jinit_downsampler().
00189 {
00190 /* Copy the data */
00191 jcopy_sample_rows(input_data, 0, output_data, 0,
00192 cinfo->max_v_samp_factor, cinfo->image_width);
00193 /* Edge-expand */
00194 expand_right_edge(output_data, cinfo->max_v_samp_factor,
00195 cinfo->image_width, compptr->width_in_blocks * DCTSIZE);
00196 }
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Definition at line 392 of file jcsample.c. References compptr, expand_right_edge(), GETJSAMPLE, jpeg_compress_struct::image_width, INT32, JDIMENSION, JSAMPARRAY, JSAMPROW, L, jpeg_compress_struct::max_v_samp_factor, jpeg_compress_struct::smoothing_factor, jpeg_component_info::v_samp_factor, and jpeg_component_info::width_in_blocks. Referenced by jinit_downsampler().
00394 {
00395 int outrow;
00396 JDIMENSION colctr;
00397 JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
00398 register JSAMPROW inptr, above_ptr, below_ptr, outptr;
00399 INT32 membersum, neighsum, memberscale, neighscale;
00400 int colsum, lastcolsum, nextcolsum;
00401
00402 /* Expand input data enough to let all the output samples be generated
00403 * by the standard loop. Special-casing padded output would be more
00404 * efficient.
00405 */
00406 expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
00407 cinfo->image_width, output_cols);
00408
00409 /* Each of the eight neighbor pixels contributes a fraction SF to the
00410 * smoothed pixel, while the main pixel contributes (1-8*SF). In order
00411 * to use integer arithmetic, these factors are multiplied by 2^16 = 65536.
00412 * Also recall that SF = smoothing_factor / 1024.
00413 */
00414
00415 memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */
00416 neighscale = cinfo->smoothing_factor * 64; /* scaled SF */
00417
00418 for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
00419 outptr = output_data[outrow];
00420 inptr = input_data[outrow];
00421 above_ptr = input_data[outrow-1];
00422 below_ptr = input_data[outrow+1];
00423
00424 /* Special case for first column */
00425 colsum = GETJSAMPLE(*above_ptr++) + GETJSAMPLE(*below_ptr++) +
00426 GETJSAMPLE(*inptr);
00427 membersum = GETJSAMPLE(*inptr++);
00428 nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) +
00429 GETJSAMPLE(*inptr);
00430 neighsum = colsum + (colsum - membersum) + nextcolsum;
00431 membersum = membersum * memberscale + neighsum * neighscale;
00432 *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
00433 lastcolsum = colsum; colsum = nextcolsum;
00434
00435 for (colctr = output_cols - 2; colctr > 0; colctr--) {
00436 membersum = GETJSAMPLE(*inptr++);
00437 above_ptr++; below_ptr++;
00438 nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) +
00439 GETJSAMPLE(*inptr);
00440 neighsum = lastcolsum + (colsum - membersum) + nextcolsum;
00441 membersum = membersum * memberscale + neighsum * neighscale;
00442 *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
00443 lastcolsum = colsum; colsum = nextcolsum;
00444 }
00445
00446 /* Special case for last column */
00447 membersum = GETJSAMPLE(*inptr);
00448 neighsum = lastcolsum + (colsum - membersum) + colsum;
00449 membersum = membersum * memberscale + neighsum * neighscale;
00450 *outptr = (JSAMPLE) ((membersum + 32768) >> 16);
00451
00452 }
00453 }
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Definition at line 212 of file jcsample.c. References compptr, expand_right_edge(), GETJSAMPLE, jpeg_compress_struct::image_width, JDIMENSION, JSAMPARRAY, JSAMPROW, jpeg_compress_struct::max_v_samp_factor, jpeg_component_info::v_samp_factor, and jpeg_component_info::width_in_blocks. Referenced by jinit_downsampler().
00214 {
00215 int outrow;
00216 JDIMENSION outcol;
00217 JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
00218 register JSAMPROW inptr, outptr;
00219 register int bias;
00220
00221 /* Expand input data enough to let all the output samples be generated
00222 * by the standard loop. Special-casing padded output would be more
00223 * efficient.
00224 */
00225 expand_right_edge(input_data, cinfo->max_v_samp_factor,
00226 cinfo->image_width, output_cols * 2);
00227
00228 for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
00229 outptr = output_data[outrow];
00230 inptr = input_data[outrow];
00231 bias = 0; /* bias = 0,1,0,1,... for successive samples */
00232 for (outcol = 0; outcol < output_cols; outcol++) {
00233 *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1])
00234 + bias) >> 1);
00235 bias ^= 1; /* 0=>1, 1=>0 */
00236 inptr += 2;
00237 }
00238 }
00239 }
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Definition at line 249 of file jcsample.c. References compptr, expand_right_edge(), GETJSAMPLE, jpeg_compress_struct::image_width, JDIMENSION, JSAMPARRAY, JSAMPROW, jpeg_compress_struct::max_v_samp_factor, jpeg_component_info::v_samp_factor, and jpeg_component_info::width_in_blocks. Referenced by jinit_downsampler().
00251 {
00252 int inrow, outrow;
00253 JDIMENSION outcol;
00254 JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
00255 register JSAMPROW inptr0, inptr1, outptr;
00256 register int bias;
00257
00258 /* Expand input data enough to let all the output samples be generated
00259 * by the standard loop. Special-casing padded output would be more
00260 * efficient.
00261 */
00262 expand_right_edge(input_data, cinfo->max_v_samp_factor,
00263 cinfo->image_width, output_cols * 2);
00264
00265 inrow = 0;
00266 for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
00267 outptr = output_data[outrow];
00268 inptr0 = input_data[inrow];
00269 inptr1 = input_data[inrow+1];
00270 bias = 1; /* bias = 1,2,1,2,... for successive samples */
00271 for (outcol = 0; outcol < output_cols; outcol++) {
00272 *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
00273 GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1])
00274 + bias) >> 2);
00275 bias ^= 3; /* 1=>2, 2=>1 */
00276 inptr0 += 2; inptr1 += 2;
00277 }
00278 inrow += 2;
00279 }
00280 }
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Definition at line 292 of file jcsample.c. References compptr, expand_right_edge(), GETJSAMPLE, jpeg_compress_struct::image_width, INT32, JDIMENSION, JSAMPARRAY, JSAMPROW, jpeg_compress_struct::max_v_samp_factor, jpeg_compress_struct::smoothing_factor, jpeg_component_info::v_samp_factor, and jpeg_component_info::width_in_blocks. Referenced by jinit_downsampler().
00294 {
00295 int inrow, outrow;
00296 JDIMENSION colctr;
00297 JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
00298 register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
00299 INT32 membersum, neighsum, memberscale, neighscale;
00300
00301 /* Expand input data enough to let all the output samples be generated
00302 * by the standard loop. Special-casing padded output would be more
00303 * efficient.
00304 */
00305 expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
00306 cinfo->image_width, output_cols * 2);
00307
00308 /* We don't bother to form the individual "smoothed" input pixel values;
00309 * we can directly compute the output which is the average of the four
00310 * smoothed values. Each of the four member pixels contributes a fraction
00311 * (1-8*SF) to its own smoothed image and a fraction SF to each of the three
00312 * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final
00313 * output. The four corner-adjacent neighbor pixels contribute a fraction
00314 * SF to just one smoothed pixel, or SF/4 to the final output; while the
00315 * eight edge-adjacent neighbors contribute SF to each of two smoothed
00316 * pixels, or SF/2 overall. In order to use integer arithmetic, these
00317 * factors are scaled by 2^16 = 65536.
00318 * Also recall that SF = smoothing_factor / 1024.
00319 */
00320
00321 memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */
00322 neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */
00323
00324 inrow = 0;
00325 for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
00326 outptr = output_data[outrow];
00327 inptr0 = input_data[inrow];
00328 inptr1 = input_data[inrow+1];
00329 above_ptr = input_data[inrow-1];
00330 below_ptr = input_data[inrow+2];
00331
00332 /* Special case for first column: pretend column -1 is same as column 0 */
00333 membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
00334 GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
00335 neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
00336 GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
00337 GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[2]) +
00338 GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[2]);
00339 neighsum += neighsum;
00340 neighsum += GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[2]) +
00341 GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[2]);
00342 membersum = membersum * memberscale + neighsum * neighscale;
00343 *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
00344 inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2;
00345
00346 for (colctr = output_cols - 2; colctr > 0; colctr--) {
00347 /* sum of pixels directly mapped to this output element */
00348 membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
00349 GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
00350 /* sum of edge-neighbor pixels */
00351 neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
00352 GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
00353 GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[2]) +
00354 GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[2]);
00355 /* The edge-neighbors count twice as much as corner-neighbors */
00356 neighsum += neighsum;
00357 /* Add in the corner-neighbors */
00358 neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[2]) +
00359 GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[2]);
00360 /* form final output scaled up by 2^16 */
00361 membersum = membersum * memberscale + neighsum * neighscale;
00362 /* round, descale and output it */
00363 *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
00364 inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2;
00365 }
00366
00367 /* Special case for last column */
00368 membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
00369 GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
00370 neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
00371 GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
00372 GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[1]) +
00373 GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[1]);
00374 neighsum += neighsum;
00375 neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[1]) +
00376 GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[1]);
00377 membersum = membersum * memberscale + neighsum * neighscale;
00378 *outptr = (JSAMPLE) ((membersum + 32768) >> 16);
00379
00380 inrow += 2;
00381 }
00382 }
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Definition at line 140 of file jcsample.c. References compptr, expand_right_edge(), GETJSAMPLE, jpeg_component_info::h_samp_factor, jpeg_compress_struct::image_width, INT32, JDIMENSION, JSAMPARRAY, JSAMPROW, jpeg_compress_struct::max_h_samp_factor, jpeg_compress_struct::max_v_samp_factor, v, jpeg_component_info::v_samp_factor, and jpeg_component_info::width_in_blocks. Referenced by jinit_downsampler().
00142 {
00143 int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v;
00144 JDIMENSION outcol, outcol_h; /* outcol_h == outcol*h_expand */
00145 JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
00146 JSAMPROW inptr, outptr;
00147 INT32 outvalue;
00148
00149 h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor;
00150 v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor;
00151 numpix = h_expand * v_expand;
00152 numpix2 = numpix/2;
00153
00154 /* Expand input data enough to let all the output samples be generated
00155 * by the standard loop. Special-casing padded output would be more
00156 * efficient.
00157 */
00158 expand_right_edge(input_data, cinfo->max_v_samp_factor,
00159 cinfo->image_width, output_cols * h_expand);
00160
00161 inrow = 0;
00162 for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
00163 outptr = output_data[outrow];
00164 for (outcol = 0, outcol_h = 0; outcol < output_cols;
00165 outcol++, outcol_h += h_expand) {
00166 outvalue = 0;
00167 for (v = 0; v < v_expand; v++) {
00168 inptr = input_data[inrow+v] + outcol_h;
00169 for (h = 0; h < h_expand; h++) {
00170 outvalue += (INT32) GETJSAMPLE(*inptr++);
00171 }
00172 }
00173 *outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix);
00174 }
00175 inrow += v_expand;
00176 }
00177 }
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Definition at line 464 of file jcsample.c. References compptr, ERREXIT, fullsize_downsample(), fullsize_smooth_downsample(), h2v1_downsample(), h2v2_downsample(), h2v2_smooth_downsample(), jpeg_component_info::h_samp_factor, int_downsample(), JPOOL_IMAGE, JTRC_SMOOTH_NOTIMPL, jpeg_downsampler::need_context_rows, sep_downsample(), SIZEOF, start_pass_downsample(), TRACEMS, and jpeg_component_info::v_samp_factor. Referenced by jinit_compress_master().
00465 {
00466 my_downsample_ptr downsample;
00467 int ci;
00468 jpeg_component_info * compptr;
00469 boolean smoothok = TRUE;
00470
00471 downsample = (my_downsample_ptr)
00472 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
00473 SIZEOF(my_downsampler));
00474 cinfo->downsample = (struct jpeg_downsampler *) downsample;
00475 downsample->pub.start_pass = start_pass_downsample;
00476 downsample->pub.downsample = sep_downsample;
00477 downsample->pub.need_context_rows = FALSE;
00478
00479 if (cinfo->CCIR601_sampling)
00480 ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
00481
00482 /* Verify we can handle the sampling factors, and set up method pointers */
00483 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
00484 ci++, compptr++) {
00485 if (compptr->h_samp_factor == cinfo->max_h_samp_factor &&
00486 compptr->v_samp_factor == cinfo->max_v_samp_factor) {
00487 #ifdef INPUT_SMOOTHING_SUPPORTED
00488 if (cinfo->smoothing_factor) {
00489 downsample->methods[ci] = fullsize_smooth_downsample;
00490 downsample->pub.need_context_rows = TRUE;
00491 } else
00492 #endif
00493 downsample->methods[ci] = fullsize_downsample;
00494 } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
00495 compptr->v_samp_factor == cinfo->max_v_samp_factor) {
00496 smoothok = FALSE;
00497 downsample->methods[ci] = h2v1_downsample;
00498 } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
00499 compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) {
00500 #ifdef INPUT_SMOOTHING_SUPPORTED
00501 if (cinfo->smoothing_factor) {
00502 downsample->methods[ci] = h2v2_smooth_downsample;
00503 downsample->pub.need_context_rows = TRUE;
00504 } else
00505 #endif
00506 downsample->methods[ci] = h2v2_downsample;
00507 } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 &&
00508 (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) {
00509 smoothok = FALSE;
00510 downsample->methods[ci] = int_downsample;
00511 } else
00512 ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
00513 }
00514
00515 #ifdef INPUT_SMOOTHING_SUPPORTED
00516 if (cinfo->smoothing_factor && !smoothok)
00517 TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL);
00518 #endif
00519 }
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Definition at line 114 of file jcsample.c. References jpeg_compress_struct::comp_info, compptr, jpeg_compress_struct::downsample, JDIMENSION, JSAMPARRAY, JSAMPIMAGE, my_downsampler::methods, jpeg_compress_struct::num_components, and jpeg_component_info::v_samp_factor. Referenced by jinit_downsampler().
00117 {
00118 my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample;
00119 int ci;
00120 jpeg_component_info * compptr;
00121 JSAMPARRAY in_ptr, out_ptr;
00122
00123 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
00124 ci++, compptr++) {
00125 in_ptr = input_buf[ci] + in_row_index;
00126 out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor);
00127 (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr);
00128 }
00129 }
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Definition at line 75 of file jcsample.c. Referenced by jinit_downsampler().
00076 {
00077 /* no work for now */
00078 }
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