media/libjpeg/jcsample.c

   1 /*
   2  * jcsample.c
   3  *
   4  * This file was part of the Independent JPEG Group's software:
   5  * Copyright (C) 1991-1996, Thomas G. Lane.
   6  * Lossless JPEG Modifications:
   7  * Copyright (C) 1999, Ken Murchison.
   8  * libjpeg-turbo Modifications:
   9  * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
  10  * Copyright (C) 2014, MIPS Technologies, Inc., California.
  11  * Copyright (C) 2015, 2019, 2022, D. R. Commander.
  12  * For conditions of distribution and use, see the accompanying README.ijg
  13  * file.
  14  *
  15  * This file contains downsampling routines.
  16  *
  17  * Downsampling input data is counted in "row groups".  A row group
  18  * is defined to be max_v_samp_factor pixel rows of each component,
  19  * from which the downsampler produces v_samp_factor sample rows.
  20  * A single row group is processed in each call to the downsampler module.
  21  *
  22  * The downsampler is responsible for edge-expansion of its output data
  23  * to fill an integral number of DCT blocks horizontally.  The source buffer
  24  * may be modified if it is helpful for this purpose (the source buffer is
  25  * allocated wide enough to correspond to the desired output width).
  26  * The caller (the prep controller) is responsible for vertical padding.
  27  *
  28  * The downsampler may request "context rows" by setting need_context_rows
  29  * during startup.  In this case, the input arrays will contain at least
  30  * one row group's worth of pixels above and below the passed-in data;
  31  * the caller will create dummy rows at image top and bottom by replicating
  32  * the first or last real pixel row.
  33  *
  34  * An excellent reference for image resampling is
  35  *   Digital Image Warping, George Wolberg, 1990.
  36  *   Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
  37  *
  38  * The downsampling algorithm used here is a simple average of the source
  39  * pixels covered by the output pixel.  The hi-falutin sampling literature
  40  * refers to this as a "box filter".  In general the characteristics of a box
  41  * filter are not very good, but for the specific cases we normally use (1:1
  42  * and 2:1 ratios) the box is equivalent to a "triangle filter" which is not
  43  * nearly so bad.  If you intend to use other sampling ratios, you'd be well
  44  * advised to improve this code.
  45  *
  46  * A simple input-smoothing capability is provided.  This is mainly intended
  47  * for cleaning up color-dithered GIF input files (if you find it inadequate,
  48  * we suggest using an external filtering program such as pnmconvol).  When
  49  * enabled, each input pixel P is replaced by a weighted sum of itself and its
  50  * eight neighbors.  P's weight is 1-8*SF and each neighbor's weight is SF,
  51  * where SF = (smoothing_factor / 1024).
  52  * Currently, smoothing is only supported for 2h2v sampling factors.
  53  */
  54
  55 #define JPEG_INTERNALS
  56 #include "jinclude.h"
  57 #include "jpeglib.h"
  58 #include "jsimd.h"
  59 #include "jsamplecomp.h"
  60
  61
  62 #if BITS_IN_JSAMPLE != 16 || defined(C_LOSSLESS_SUPPORTED)
  63
  64 /* Pointer to routine to downsample a single component */
  65 typedef void (*downsample1_ptr) (j_compress_ptr cinfo,
  66                                  jpeg_component_info *compptr,
  67                                  _JSAMPARRAY input_data,
  68                                  _JSAMPARRAY output_data);
  69
  70 /* Private subobject */
  71
  72 typedef struct {
  73   struct jpeg_downsampler pub;  /* public fields */
  74
  75   /* Downsampling method pointers, one per component */
  76   downsample1_ptr methods[MAX_COMPONENTS];
  77 } my_downsampler;
  78
  79 typedef my_downsampler *my_downsample_ptr;
  80
  81
  82 /*
  83  * Initialize for a downsampling pass.
  84  */
  85
  86 METHODDEF(void)
  87 start_pass_downsample(j_compress_ptr cinfo)
  88 {
  89   /* no work for now */
  90 }
  91
  92
  93 /*
  94  * Expand a component horizontally from width input_cols to width output_cols,
  95  * by duplicating the rightmost samples.
  96  */
  97
  98 LOCAL(void)
  99 expand_right_edge(_JSAMPARRAY image_data, int num_rows, JDIMENSION input_cols,
 100                   JDIMENSION output_cols)
 101 {
 102   register _JSAMPROW ptr;
 103   register _JSAMPLE pixval;
 104   register int count;
 105   int row;
 106   int numcols = (int)(output_cols - input_cols);
 107
 108   if (numcols > 0) {
 109     for (row = 0; row < num_rows; row++) {
 110       ptr = image_data[row] + input_cols;
 111       pixval = ptr[-1];
 112       for (count = numcols; count > 0; count--)
 113         *ptr++ = pixval;
 114     }
 115   }
 116 }
 117
 118
 119 /*
 120  * Do downsampling for a whole row group (all components).
 121  *
 122  * In this version we simply downsample each component independently.
 123  */
 124
 125 METHODDEF(void)
 126 sep_downsample(j_compress_ptr cinfo, _JSAMPIMAGE input_buf,
 127                JDIMENSION in_row_index, _JSAMPIMAGE output_buf,
 128                JDIMENSION out_row_group_index)
 129 {
 130   my_downsample_ptr downsample = (my_downsample_ptr)cinfo->downsample;
 131   int ci;
 132   jpeg_component_info *compptr;
 133   _JSAMPARRAY in_ptr, out_ptr;
 134
 135   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 136        ci++, compptr++) {
 137     in_ptr = input_buf[ci] + in_row_index;
 138     out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor);
 139     (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr);
 140   }
 141 }
 142
 143
 144 /*
 145  * Downsample pixel values of a single component.
 146  * One row group is processed per call.
 147  * This version handles arbitrary integral sampling ratios, without smoothing.
 148  * Note that this version is not actually used for customary sampling ratios.
 149  */
 150
 151 METHODDEF(void)
 152 int_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
 153                _JSAMPARRAY input_data, _JSAMPARRAY output_data)
 154 {
 155   int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v;
 156   JDIMENSION outcol, outcol_h;  /* outcol_h == outcol*h_expand */
 157   int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;
 158   JDIMENSION output_cols = compptr->width_in_blocks * data_unit;
 159   _JSAMPROW inptr, outptr;
 160   JLONG outvalue;
 161
 162   h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor;
 163   v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor;
 164   numpix = h_expand * v_expand;
 165   numpix2 = numpix / 2;
 166
 167   /* Expand input data enough to let all the output samples be generated
 168    * by the standard loop.  Special-casing padded output would be more
 169    * efficient.
 170    */
 171   expand_right_edge(input_data, cinfo->max_v_samp_factor, cinfo->image_width,
 172                     output_cols * h_expand);
 173
 174   inrow = 0;
 175   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
 176     outptr = output_data[outrow];
 177     for (outcol = 0, outcol_h = 0; outcol < output_cols;
 178          outcol++, outcol_h += h_expand) {
 179       outvalue = 0;
 180       for (v = 0; v < v_expand; v++) {
 181         inptr = input_data[inrow + v] + outcol_h;
 182         for (h = 0; h < h_expand; h++) {
 183           outvalue += (JLONG)(*inptr++);
 184         }
 185       }
 186       *outptr++ = (_JSAMPLE)((outvalue + numpix2) / numpix);
 187     }
 188     inrow += v_expand;
 189   }
 190 }
 191
 192
 193 /*
 194  * Downsample pixel values of a single component.
 195  * This version handles the special case of a full-size component,
 196  * without smoothing.
 197  */
 198
 199 METHODDEF(void)
 200 fullsize_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
 201                     _JSAMPARRAY input_data, _JSAMPARRAY output_data)
 202 {
 203   int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;
 204
 205   /* Copy the data */
 206   _jcopy_sample_rows(input_data, 0, output_data, 0, cinfo->max_v_samp_factor,
 207                      cinfo->image_width);
 208   /* Edge-expand */
 209   expand_right_edge(output_data, cinfo->max_v_samp_factor, cinfo->image_width,
 210                     compptr->width_in_blocks * data_unit);
 211 }
 212
 213
 214 /*
 215  * Downsample pixel values of a single component.
 216  * This version handles the common case of 2:1 horizontal and 1:1 vertical,
 217  * without smoothing.
 218  *
 219  * A note about the "bias" calculations: when rounding fractional values to
 220  * integer, we do not want to always round 0.5 up to the next integer.
 221  * If we did that, we'd introduce a noticeable bias towards larger values.
 222  * Instead, this code is arranged so that 0.5 will be rounded up or down at
 223  * alternate pixel locations (a simple ordered dither pattern).
 224  */
 225
 226 METHODDEF(void)
 227 h2v1_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
 228                 _JSAMPARRAY input_data, _JSAMPARRAY output_data)
 229 {
 230   int outrow;
 231   JDIMENSION outcol;
 232   int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;
 233   JDIMENSION output_cols = compptr->width_in_blocks * data_unit;
 234   register _JSAMPROW inptr, outptr;
 235   register int bias;
 236
 237   /* Expand input data enough to let all the output samples be generated
 238    * by the standard loop.  Special-casing padded output would be more
 239    * efficient.
 240    */
 241   expand_right_edge(input_data, cinfo->max_v_samp_factor, cinfo->image_width,
 242                     output_cols * 2);
 243
 244   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
 245     outptr = output_data[outrow];
 246     inptr = input_data[outrow];
 247     bias = 0;                   /* bias = 0,1,0,1,... for successive samples */
 248     for (outcol = 0; outcol < output_cols; outcol++) {
 249       *outptr++ = (_JSAMPLE)((inptr[0] + inptr[1] + bias) >> 1);
 250       bias ^= 1;                /* 0=>1, 1=>0 */
 251       inptr += 2;
 252     }
 253   }
 254 }
 255
 256
 257 /*
 258  * Downsample pixel values of a single component.
 259  * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
 260  * without smoothing.
 261  */
 262
 263 METHODDEF(void)
 264 h2v2_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
 265                 _JSAMPARRAY input_data, _JSAMPARRAY output_data)
 266 {
 267   int inrow, outrow;
 268   JDIMENSION outcol;
 269   int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;
 270   JDIMENSION output_cols = compptr->width_in_blocks * data_unit;
 271   register _JSAMPROW inptr0, inptr1, outptr;
 272   register int bias;
 273
 274   /* Expand input data enough to let all the output samples be generated
 275    * by the standard loop.  Special-casing padded output would be more
 276    * efficient.
 277    */
 278   expand_right_edge(input_data, cinfo->max_v_samp_factor, cinfo->image_width,
 279                     output_cols * 2);
 280
 281   inrow = 0;
 282   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
 283     outptr = output_data[outrow];
 284     inptr0 = input_data[inrow];
 285     inptr1 = input_data[inrow + 1];
 286     bias = 1;                   /* bias = 1,2,1,2,... for successive samples */
 287     for (outcol = 0; outcol < output_cols; outcol++) {
 288       *outptr++ = (_JSAMPLE)
 289         ((inptr0[0] + inptr0[1] + inptr1[0] + inptr1[1] + bias) >> 2);
 290       bias ^= 3;                /* 1=>2, 2=>1 */
 291       inptr0 += 2;  inptr1 += 2;
 292     }
 293     inrow += 2;
 294   }
 295 }
 296
 297
 298 #ifdef INPUT_SMOOTHING_SUPPORTED
 299
 300 /*
 301  * Downsample pixel values of a single component.
 302  * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
 303  * with smoothing.  One row of context is required.
 304  */
 305
 306 METHODDEF(void)
 307 h2v2_smooth_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
 308                        _JSAMPARRAY input_data, _JSAMPARRAY output_data)
 309 {
 310   int inrow, outrow;
 311   JDIMENSION colctr;
 312   int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;
 313   JDIMENSION output_cols = compptr->width_in_blocks * data_unit;
 314   register _JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
 315   JLONG membersum, neighsum, memberscale, neighscale;
 316
 317   /* Expand input data enough to let all the output samples be generated
 318    * by the standard loop.  Special-casing padded output would be more
 319    * efficient.
 320    */
 321   expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
 322                     cinfo->image_width, output_cols * 2);
 323
 324   /* We don't bother to form the individual "smoothed" input pixel values;
 325    * we can directly compute the output which is the average of the four
 326    * smoothed values.  Each of the four member pixels contributes a fraction
 327    * (1-8*SF) to its own smoothed image and a fraction SF to each of the three
 328    * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final
 329    * output.  The four corner-adjacent neighbor pixels contribute a fraction
 330    * SF to just one smoothed pixel, or SF/4 to the final output; while the
 331    * eight edge-adjacent neighbors contribute SF to each of two smoothed
 332    * pixels, or SF/2 overall.  In order to use integer arithmetic, these
 333    * factors are scaled by 2^16 = 65536.
 334    * Also recall that SF = smoothing_factor / 1024.
 335    */
 336
 337   memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */
 338   neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */
 339
 340   inrow = 0;
 341   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
 342     outptr = output_data[outrow];
 343     inptr0 = input_data[inrow];
 344     inptr1 = input_data[inrow + 1];
 345     above_ptr = input_data[inrow - 1];
 346     below_ptr = input_data[inrow + 2];
 347
 348     /* Special case for first column: pretend column -1 is same as column 0 */
 349     membersum = inptr0[0] + inptr0[1] + inptr1[0] + inptr1[1];
 350     neighsum = above_ptr[0] + above_ptr[1] + below_ptr[0] + below_ptr[1] +
 351                inptr0[0] + inptr0[2] + inptr1[0] + inptr1[2];
 352     neighsum += neighsum;
 353     neighsum += above_ptr[0] + above_ptr[2] + below_ptr[0] + below_ptr[2];
 354     membersum = membersum * memberscale + neighsum * neighscale;
 355     *outptr++ = (_JSAMPLE)((membersum + 32768) >> 16);
 356     inptr0 += 2;  inptr1 += 2;  above_ptr += 2;  below_ptr += 2;
 357
 358     for (colctr = output_cols - 2; colctr > 0; colctr--) {
 359       /* sum of pixels directly mapped to this output element */
 360       membersum = inptr0[0] + inptr0[1] + inptr1[0] + inptr1[1];
 361       /* sum of edge-neighbor pixels */
 362       neighsum = above_ptr[0] + above_ptr[1] + below_ptr[0] + below_ptr[1] +
 363                  inptr0[-1] + inptr0[2] + inptr1[-1] + inptr1[2];
 364       /* The edge-neighbors count twice as much as corner-neighbors */
 365       neighsum += neighsum;
 366       /* Add in the corner-neighbors */
 367       neighsum += above_ptr[-1] + above_ptr[2] + below_ptr[-1] + below_ptr[2];
 368       /* form final output scaled up by 2^16 */
 369       membersum = membersum * memberscale + neighsum * neighscale;
 370       /* round, descale and output it */
 371       *outptr++ = (_JSAMPLE)((membersum + 32768) >> 16);
 372       inptr0 += 2;  inptr1 += 2;  above_ptr += 2;  below_ptr += 2;
 373     }
 374
 375     /* Special case for last column */
 376     membersum = inptr0[0] + inptr0[1] + inptr1[0] + inptr1[1];
 377     neighsum = above_ptr[0] + above_ptr[1] + below_ptr[0] + below_ptr[1] +
 378                inptr0[-1] + inptr0[1] + inptr1[-1] + inptr1[1];
 379     neighsum += neighsum;
 380     neighsum += above_ptr[-1] + above_ptr[1] + below_ptr[-1] + below_ptr[1];
 381     membersum = membersum * memberscale + neighsum * neighscale;
 382     *outptr = (_JSAMPLE)((membersum + 32768) >> 16);
 383
 384     inrow += 2;
 385   }
 386 }
 387
 388
 389 /*
 390  * Downsample pixel values of a single component.
 391  * This version handles the special case of a full-size component,
 392  * with smoothing.  One row of context is required.
 393  */
 394
 395 METHODDEF(void)
 396 fullsize_smooth_downsample(j_compress_ptr cinfo, jpeg_component_info *compptr,
 397                            _JSAMPARRAY input_data, _JSAMPARRAY output_data)
 398 {
 399   int outrow;
 400   JDIMENSION colctr;
 401   int data_unit = cinfo->master->lossless ? 1 : DCTSIZE;
 402   JDIMENSION output_cols = compptr->width_in_blocks * data_unit;
 403   register _JSAMPROW inptr, above_ptr, below_ptr, outptr;
 404   JLONG membersum, neighsum, memberscale, neighscale;
 405   int colsum, lastcolsum, nextcolsum;
 406
 407   /* Expand input data enough to let all the output samples be generated
 408    * by the standard loop.  Special-casing padded output would be more
 409    * efficient.
 410    */
 411   expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
 412                     cinfo->image_width, output_cols);
 413
 414   /* Each of the eight neighbor pixels contributes a fraction SF to the
 415    * smoothed pixel, while the main pixel contributes (1-8*SF).  In order
 416    * to use integer arithmetic, these factors are multiplied by 2^16 = 65536.
 417    * Also recall that SF = smoothing_factor / 1024.
 418    */
 419
 420   memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */
 421   neighscale = cinfo->smoothing_factor * 64; /* scaled SF */
 422
 423   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
 424     outptr = output_data[outrow];
 425     inptr = input_data[outrow];
 426     above_ptr = input_data[outrow - 1];
 427     below_ptr = input_data[outrow + 1];
 428
 429     /* Special case for first column */
 430     colsum = (*above_ptr++) + (*below_ptr++) + inptr[0];
 431     membersum = *inptr++;
 432     nextcolsum = above_ptr[0] + below_ptr[0] + inptr[0];
 433     neighsum = colsum + (colsum - membersum) + nextcolsum;
 434     membersum = membersum * memberscale + neighsum * neighscale;
 435     *outptr++ = (_JSAMPLE)((membersum + 32768) >> 16);
 436     lastcolsum = colsum;  colsum = nextcolsum;
 437
 438     for (colctr = output_cols - 2; colctr > 0; colctr--) {
 439       membersum = *inptr++;
 440       above_ptr++;  below_ptr++;
 441       nextcolsum = above_ptr[0] + below_ptr[0] + inptr[0];
 442       neighsum = lastcolsum + (colsum - membersum) + nextcolsum;
 443       membersum = membersum * memberscale + neighsum * neighscale;
 444       *outptr++ = (_JSAMPLE)((membersum + 32768) >> 16);
 445       lastcolsum = colsum;  colsum = nextcolsum;
 446     }
 447
 448     /* Special case for last column */
 449     membersum = *inptr;
 450     neighsum = lastcolsum + (colsum - membersum) + colsum;
 451     membersum = membersum * memberscale + neighsum * neighscale;
 452     *outptr = (_JSAMPLE)((membersum + 32768) >> 16);
 453
 454   }
 455 }
 456
 457 #endif /* INPUT_SMOOTHING_SUPPORTED */
 458
 459
 460 /*
 461  * Module initialization routine for downsampling.
 462  * Note that we must select a routine for each component.
 463  */
 464
 465 GLOBAL(void)
 466 _jinit_downsampler(j_compress_ptr cinfo)
 467 {
 468   my_downsample_ptr downsample;
 469   int ci;
 470   jpeg_component_info *compptr;
 471   boolean smoothok = TRUE;
 472
 473   if (cinfo->data_precision != BITS_IN_JSAMPLE)
 474     ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
 475
 476   downsample = (my_downsample_ptr)
 477     (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
 478                                 sizeof(my_downsampler));
 479   cinfo->downsample = (struct jpeg_downsampler *)downsample;
 480   downsample->pub.start_pass = start_pass_downsample;
 481   downsample->pub._downsample = sep_downsample;
 482   downsample->pub.need_context_rows = FALSE;
 483
 484   if (cinfo->CCIR601_sampling)
 485     ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
 486
 487   /* Verify we can handle the sampling factors, and set up method pointers */
 488   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 489        ci++, compptr++) {
 490     if (compptr->h_samp_factor == cinfo->max_h_samp_factor &&
 491         compptr->v_samp_factor == cinfo->max_v_samp_factor) {
 492 #ifdef INPUT_SMOOTHING_SUPPORTED
 493       if (cinfo->smoothing_factor) {
 494         downsample->methods[ci] = fullsize_smooth_downsample;
 495         downsample->pub.need_context_rows = TRUE;
 496       } else
 497 #endif
 498         downsample->methods[ci] = fullsize_downsample;
 499     } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
 500                compptr->v_samp_factor == cinfo->max_v_samp_factor) {
 501       smoothok = FALSE;
 502 #ifdef WITH_SIMD
 503       if (jsimd_can_h2v1_downsample())
 504         downsample->methods[ci] = jsimd_h2v1_downsample;
 505       else
 506 #endif
 507         downsample->methods[ci] = h2v1_downsample;
 508     } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
 509                compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) {
 510 #ifdef INPUT_SMOOTHING_SUPPORTED
 511       if (cinfo->smoothing_factor) {
 512 #if defined(WITH_SIMD) && defined(__mips__)
 513         if (jsimd_can_h2v2_smooth_downsample())
 514           downsample->methods[ci] = jsimd_h2v2_smooth_downsample;
 515         else
 516 #endif
 517           downsample->methods[ci] = h2v2_smooth_downsample;
 518         downsample->pub.need_context_rows = TRUE;
 519       } else
 520 #endif
 521       {
 522 #ifdef WITH_SIMD
 523         if (jsimd_can_h2v2_downsample())
 524           downsample->methods[ci] = jsimd_h2v2_downsample;
 525         else
 526 #endif
 527           downsample->methods[ci] = h2v2_downsample;
 528       }
 529     } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 &&
 530                (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) {
 531       smoothok = FALSE;
 532       downsample->methods[ci] = int_downsample;
 533     } else
 534       ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
 535   }
 536
 537 #ifdef INPUT_SMOOTHING_SUPPORTED
 538   if (cinfo->smoothing_factor && !smoothok)
 539     TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL);
 540 #endif
 541 }
 542
 543 #endif /* BITS_IN_JSAMPLE != 16 || defined(C_LOSSLESS_SUPPORTED) */