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annotate libs/libjpeg/jccolor.c @ 26:862a3329a8f0

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wohooo, added a shitload of code from zlib/libpng/libjpeg. When the good lord was raining shared libraries the iphone held a fucking umbrella...
author John Tsiombikas <nuclear@mutantstargoat.com>
date Thu, 08 Sep 2011 06:28:38 +0300
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nuclear@26 1 /*
nuclear@26 2 * jccolor.c
nuclear@26 3 *
nuclear@26 4 * Copyright (C) 1991-1996, Thomas G. Lane.
nuclear@26 5 * This file is part of the Independent JPEG Group's software.
nuclear@26 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@26 7 *
nuclear@26 8 * This file contains input colorspace conversion routines.
nuclear@26 9 */
nuclear@26 10
nuclear@26 11 #define JPEG_INTERNALS
nuclear@26 12 #include "jinclude.h"
nuclear@26 13 #include "jpeglib.h"
nuclear@26 14
nuclear@26 15
nuclear@26 16 /* Private subobject */
nuclear@26 17
nuclear@26 18 typedef struct {
nuclear@26 19 struct jpeg_color_converter pub; /* public fields */
nuclear@26 20
nuclear@26 21 /* Private state for RGB->YCC conversion */
nuclear@26 22 INT32 * rgb_ycc_tab; /* => table for RGB to YCbCr conversion */
nuclear@26 23 } my_color_converter;
nuclear@26 24
nuclear@26 25 typedef my_color_converter * my_cconvert_ptr;
nuclear@26 26
nuclear@26 27
nuclear@26 28 /**************** RGB -> YCbCr conversion: most common case **************/
nuclear@26 29
nuclear@26 30 /*
nuclear@26 31 * YCbCr is defined per CCIR 601-1, except that Cb and Cr are
nuclear@26 32 * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
nuclear@26 33 * The conversion equations to be implemented are therefore
nuclear@26 34 * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B
nuclear@26 35 * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE
nuclear@26 36 * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE
nuclear@26 37 * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.)
nuclear@26 38 * Note: older versions of the IJG code used a zero offset of MAXJSAMPLE/2,
nuclear@26 39 * rather than CENTERJSAMPLE, for Cb and Cr. This gave equal positive and
nuclear@26 40 * negative swings for Cb/Cr, but meant that grayscale values (Cb=Cr=0)
nuclear@26 41 * were not represented exactly. Now we sacrifice exact representation of
nuclear@26 42 * maximum red and maximum blue in order to get exact grayscales.
nuclear@26 43 *
nuclear@26 44 * To avoid floating-point arithmetic, we represent the fractional constants
nuclear@26 45 * as integers scaled up by 2^16 (about 4 digits precision); we have to divide
nuclear@26 46 * the products by 2^16, with appropriate rounding, to get the correct answer.
nuclear@26 47 *
nuclear@26 48 * For even more speed, we avoid doing any multiplications in the inner loop
nuclear@26 49 * by precalculating the constants times R,G,B for all possible values.
nuclear@26 50 * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
nuclear@26 51 * for 12-bit samples it is still acceptable. It's not very reasonable for
nuclear@26 52 * 16-bit samples, but if you want lossless storage you shouldn't be changing
nuclear@26 53 * colorspace anyway.
nuclear@26 54 * The CENTERJSAMPLE offsets and the rounding fudge-factor of 0.5 are included
nuclear@26 55 * in the tables to save adding them separately in the inner loop.
nuclear@26 56 */
nuclear@26 57
nuclear@26 58 #define SCALEBITS 16 /* speediest right-shift on some machines */
nuclear@26 59 #define CBCR_OFFSET ((INT32) CENTERJSAMPLE << SCALEBITS)
nuclear@26 60 #define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
nuclear@26 61 #define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
nuclear@26 62
nuclear@26 63 /* We allocate one big table and divide it up into eight parts, instead of
nuclear@26 64 * doing eight alloc_small requests. This lets us use a single table base
nuclear@26 65 * address, which can be held in a register in the inner loops on many
nuclear@26 66 * machines (more than can hold all eight addresses, anyway).
nuclear@26 67 */
nuclear@26 68
nuclear@26 69 #define R_Y_OFF 0 /* offset to R => Y section */
nuclear@26 70 #define G_Y_OFF (1*(MAXJSAMPLE+1)) /* offset to G => Y section */
nuclear@26 71 #define B_Y_OFF (2*(MAXJSAMPLE+1)) /* etc. */
nuclear@26 72 #define R_CB_OFF (3*(MAXJSAMPLE+1))
nuclear@26 73 #define G_CB_OFF (4*(MAXJSAMPLE+1))
nuclear@26 74 #define B_CB_OFF (5*(MAXJSAMPLE+1))
nuclear@26 75 #define R_CR_OFF B_CB_OFF /* B=>Cb, R=>Cr are the same */
nuclear@26 76 #define G_CR_OFF (6*(MAXJSAMPLE+1))
nuclear@26 77 #define B_CR_OFF (7*(MAXJSAMPLE+1))
nuclear@26 78 #define TABLE_SIZE (8*(MAXJSAMPLE+1))
nuclear@26 79
nuclear@26 80
nuclear@26 81 /*
nuclear@26 82 * Initialize for RGB->YCC colorspace conversion.
nuclear@26 83 */
nuclear@26 84
nuclear@26 85 METHODDEF(void)
nuclear@26 86 rgb_ycc_start (j_compress_ptr cinfo)
nuclear@26 87 {
nuclear@26 88 my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
nuclear@26 89 INT32 * rgb_ycc_tab;
nuclear@26 90 INT32 i;
nuclear@26 91
nuclear@26 92 /* Allocate and fill in the conversion tables. */
nuclear@26 93 cconvert->rgb_ycc_tab = rgb_ycc_tab = (INT32 *)
nuclear@26 94 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@26 95 (TABLE_SIZE * SIZEOF(INT32)));
nuclear@26 96
nuclear@26 97 for (i = 0; i <= MAXJSAMPLE; i++) {
nuclear@26 98 rgb_ycc_tab[i+R_Y_OFF] = FIX(0.29900) * i;
nuclear@26 99 rgb_ycc_tab[i+G_Y_OFF] = FIX(0.58700) * i;
nuclear@26 100 rgb_ycc_tab[i+B_Y_OFF] = FIX(0.11400) * i + ONE_HALF;
nuclear@26 101 rgb_ycc_tab[i+R_CB_OFF] = (-FIX(0.16874)) * i;
nuclear@26 102 rgb_ycc_tab[i+G_CB_OFF] = (-FIX(0.33126)) * i;
nuclear@26 103 /* We use a rounding fudge-factor of 0.5-epsilon for Cb and Cr.
nuclear@26 104 * This ensures that the maximum output will round to MAXJSAMPLE
nuclear@26 105 * not MAXJSAMPLE+1, and thus that we don't have to range-limit.
nuclear@26 106 */
nuclear@26 107 rgb_ycc_tab[i+B_CB_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1;
nuclear@26 108 /* B=>Cb and R=>Cr tables are the same
nuclear@26 109 rgb_ycc_tab[i+R_CR_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1;
nuclear@26 110 */
nuclear@26 111 rgb_ycc_tab[i+G_CR_OFF] = (-FIX(0.41869)) * i;
nuclear@26 112 rgb_ycc_tab[i+B_CR_OFF] = (-FIX(0.08131)) * i;
nuclear@26 113 }
nuclear@26 114 }
nuclear@26 115
nuclear@26 116
nuclear@26 117 /*
nuclear@26 118 * Convert some rows of samples to the JPEG colorspace.
nuclear@26 119 *
nuclear@26 120 * Note that we change from the application's interleaved-pixel format
nuclear@26 121 * to our internal noninterleaved, one-plane-per-component format.
nuclear@26 122 * The input buffer is therefore three times as wide as the output buffer.
nuclear@26 123 *
nuclear@26 124 * A starting row offset is provided only for the output buffer. The caller
nuclear@26 125 * can easily adjust the passed input_buf value to accommodate any row
nuclear@26 126 * offset required on that side.
nuclear@26 127 */
nuclear@26 128
nuclear@26 129 METHODDEF(void)
nuclear@26 130 rgb_ycc_convert (j_compress_ptr cinfo,
nuclear@26 131 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
nuclear@26 132 JDIMENSION output_row, int num_rows)
nuclear@26 133 {
nuclear@26 134 my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
nuclear@26 135 register int r, g, b;
nuclear@26 136 register INT32 * ctab = cconvert->rgb_ycc_tab;
nuclear@26 137 register JSAMPROW inptr;
nuclear@26 138 register JSAMPROW outptr0, outptr1, outptr2;
nuclear@26 139 register JDIMENSION col;
nuclear@26 140 JDIMENSION num_cols = cinfo->image_width;
nuclear@26 141
nuclear@26 142 while (--num_rows >= 0) {
nuclear@26 143 inptr = *input_buf++;
nuclear@26 144 outptr0 = output_buf[0][output_row];
nuclear@26 145 outptr1 = output_buf[1][output_row];
nuclear@26 146 outptr2 = output_buf[2][output_row];
nuclear@26 147 output_row++;
nuclear@26 148 for (col = 0; col < num_cols; col++) {
nuclear@26 149 r = GETJSAMPLE(inptr[RGB_RED]);
nuclear@26 150 g = GETJSAMPLE(inptr[RGB_GREEN]);
nuclear@26 151 b = GETJSAMPLE(inptr[RGB_BLUE]);
nuclear@26 152 inptr += RGB_PIXELSIZE;
nuclear@26 153 /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
nuclear@26 154 * must be too; we do not need an explicit range-limiting operation.
nuclear@26 155 * Hence the value being shifted is never negative, and we don't
nuclear@26 156 * need the general RIGHT_SHIFT macro.
nuclear@26 157 */
nuclear@26 158 /* Y */
nuclear@26 159 outptr0[col] = (JSAMPLE)
nuclear@26 160 ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
nuclear@26 161 >> SCALEBITS);
nuclear@26 162 /* Cb */
nuclear@26 163 outptr1[col] = (JSAMPLE)
nuclear@26 164 ((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
nuclear@26 165 >> SCALEBITS);
nuclear@26 166 /* Cr */
nuclear@26 167 outptr2[col] = (JSAMPLE)
nuclear@26 168 ((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
nuclear@26 169 >> SCALEBITS);
nuclear@26 170 }
nuclear@26 171 }
nuclear@26 172 }
nuclear@26 173
nuclear@26 174
nuclear@26 175 /**************** Cases other than RGB -> YCbCr **************/
nuclear@26 176
nuclear@26 177
nuclear@26 178 /*
nuclear@26 179 * Convert some rows of samples to the JPEG colorspace.
nuclear@26 180 * This version handles RGB->grayscale conversion, which is the same
nuclear@26 181 * as the RGB->Y portion of RGB->YCbCr.
nuclear@26 182 * We assume rgb_ycc_start has been called (we only use the Y tables).
nuclear@26 183 */
nuclear@26 184
nuclear@26 185 METHODDEF(void)
nuclear@26 186 rgb_gray_convert (j_compress_ptr cinfo,
nuclear@26 187 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
nuclear@26 188 JDIMENSION output_row, int num_rows)
nuclear@26 189 {
nuclear@26 190 my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
nuclear@26 191 register int r, g, b;
nuclear@26 192 register INT32 * ctab = cconvert->rgb_ycc_tab;
nuclear@26 193 register JSAMPROW inptr;
nuclear@26 194 register JSAMPROW outptr;
nuclear@26 195 register JDIMENSION col;
nuclear@26 196 JDIMENSION num_cols = cinfo->image_width;
nuclear@26 197
nuclear@26 198 while (--num_rows >= 0) {
nuclear@26 199 inptr = *input_buf++;
nuclear@26 200 outptr = output_buf[0][output_row];
nuclear@26 201 output_row++;
nuclear@26 202 for (col = 0; col < num_cols; col++) {
nuclear@26 203 r = GETJSAMPLE(inptr[RGB_RED]);
nuclear@26 204 g = GETJSAMPLE(inptr[RGB_GREEN]);
nuclear@26 205 b = GETJSAMPLE(inptr[RGB_BLUE]);
nuclear@26 206 inptr += RGB_PIXELSIZE;
nuclear@26 207 /* Y */
nuclear@26 208 outptr[col] = (JSAMPLE)
nuclear@26 209 ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
nuclear@26 210 >> SCALEBITS);
nuclear@26 211 }
nuclear@26 212 }
nuclear@26 213 }
nuclear@26 214
nuclear@26 215
nuclear@26 216 /*
nuclear@26 217 * Convert some rows of samples to the JPEG colorspace.
nuclear@26 218 * This version handles Adobe-style CMYK->YCCK conversion,
nuclear@26 219 * where we convert R=1-C, G=1-M, and B=1-Y to YCbCr using the same
nuclear@26 220 * conversion as above, while passing K (black) unchanged.
nuclear@26 221 * We assume rgb_ycc_start has been called.
nuclear@26 222 */
nuclear@26 223
nuclear@26 224 METHODDEF(void)
nuclear@26 225 cmyk_ycck_convert (j_compress_ptr cinfo,
nuclear@26 226 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
nuclear@26 227 JDIMENSION output_row, int num_rows)
nuclear@26 228 {
nuclear@26 229 my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
nuclear@26 230 register int r, g, b;
nuclear@26 231 register INT32 * ctab = cconvert->rgb_ycc_tab;
nuclear@26 232 register JSAMPROW inptr;
nuclear@26 233 register JSAMPROW outptr0, outptr1, outptr2, outptr3;
nuclear@26 234 register JDIMENSION col;
nuclear@26 235 JDIMENSION num_cols = cinfo->image_width;
nuclear@26 236
nuclear@26 237 while (--num_rows >= 0) {
nuclear@26 238 inptr = *input_buf++;
nuclear@26 239 outptr0 = output_buf[0][output_row];
nuclear@26 240 outptr1 = output_buf[1][output_row];
nuclear@26 241 outptr2 = output_buf[2][output_row];
nuclear@26 242 outptr3 = output_buf[3][output_row];
nuclear@26 243 output_row++;
nuclear@26 244 for (col = 0; col < num_cols; col++) {
nuclear@26 245 r = MAXJSAMPLE - GETJSAMPLE(inptr[0]);
nuclear@26 246 g = MAXJSAMPLE - GETJSAMPLE(inptr[1]);
nuclear@26 247 b = MAXJSAMPLE - GETJSAMPLE(inptr[2]);
nuclear@26 248 /* K passes through as-is */
nuclear@26 249 outptr3[col] = inptr[3]; /* don't need GETJSAMPLE here */
nuclear@26 250 inptr += 4;
nuclear@26 251 /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations
nuclear@26 252 * must be too; we do not need an explicit range-limiting operation.
nuclear@26 253 * Hence the value being shifted is never negative, and we don't
nuclear@26 254 * need the general RIGHT_SHIFT macro.
nuclear@26 255 */
nuclear@26 256 /* Y */
nuclear@26 257 outptr0[col] = (JSAMPLE)
nuclear@26 258 ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
nuclear@26 259 >> SCALEBITS);
nuclear@26 260 /* Cb */
nuclear@26 261 outptr1[col] = (JSAMPLE)
nuclear@26 262 ((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF])
nuclear@26 263 >> SCALEBITS);
nuclear@26 264 /* Cr */
nuclear@26 265 outptr2[col] = (JSAMPLE)
nuclear@26 266 ((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF])
nuclear@26 267 >> SCALEBITS);
nuclear@26 268 }
nuclear@26 269 }
nuclear@26 270 }
nuclear@26 271
nuclear@26 272
nuclear@26 273 /*
nuclear@26 274 * Convert some rows of samples to the JPEG colorspace.
nuclear@26 275 * This version handles grayscale output with no conversion.
nuclear@26 276 * The source can be either plain grayscale or YCbCr (since Y == gray).
nuclear@26 277 */
nuclear@26 278
nuclear@26 279 METHODDEF(void)
nuclear@26 280 grayscale_convert (j_compress_ptr cinfo,
nuclear@26 281 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
nuclear@26 282 JDIMENSION output_row, int num_rows)
nuclear@26 283 {
nuclear@26 284 register JSAMPROW inptr;
nuclear@26 285 register JSAMPROW outptr;
nuclear@26 286 register JDIMENSION col;
nuclear@26 287 JDIMENSION num_cols = cinfo->image_width;
nuclear@26 288 int instride = cinfo->input_components;
nuclear@26 289
nuclear@26 290 while (--num_rows >= 0) {
nuclear@26 291 inptr = *input_buf++;
nuclear@26 292 outptr = output_buf[0][output_row];
nuclear@26 293 output_row++;
nuclear@26 294 for (col = 0; col < num_cols; col++) {
nuclear@26 295 outptr[col] = inptr[0]; /* don't need GETJSAMPLE() here */
nuclear@26 296 inptr += instride;
nuclear@26 297 }
nuclear@26 298 }
nuclear@26 299 }
nuclear@26 300
nuclear@26 301
nuclear@26 302 /*
nuclear@26 303 * Convert some rows of samples to the JPEG colorspace.
nuclear@26 304 * This version handles multi-component colorspaces without conversion.
nuclear@26 305 * We assume input_components == num_components.
nuclear@26 306 */
nuclear@26 307
nuclear@26 308 METHODDEF(void)
nuclear@26 309 null_convert (j_compress_ptr cinfo,
nuclear@26 310 JSAMPARRAY input_buf, JSAMPIMAGE output_buf,
nuclear@26 311 JDIMENSION output_row, int num_rows)
nuclear@26 312 {
nuclear@26 313 register JSAMPROW inptr;
nuclear@26 314 register JSAMPROW outptr;
nuclear@26 315 register JDIMENSION col;
nuclear@26 316 register int ci;
nuclear@26 317 int nc = cinfo->num_components;
nuclear@26 318 JDIMENSION num_cols = cinfo->image_width;
nuclear@26 319
nuclear@26 320 while (--num_rows >= 0) {
nuclear@26 321 /* It seems fastest to make a separate pass for each component. */
nuclear@26 322 for (ci = 0; ci < nc; ci++) {
nuclear@26 323 inptr = *input_buf;
nuclear@26 324 outptr = output_buf[ci][output_row];
nuclear@26 325 for (col = 0; col < num_cols; col++) {
nuclear@26 326 outptr[col] = inptr[ci]; /* don't need GETJSAMPLE() here */
nuclear@26 327 inptr += nc;
nuclear@26 328 }
nuclear@26 329 }
nuclear@26 330 input_buf++;
nuclear@26 331 output_row++;
nuclear@26 332 }
nuclear@26 333 }
nuclear@26 334
nuclear@26 335
nuclear@26 336 /*
nuclear@26 337 * Empty method for start_pass.
nuclear@26 338 */
nuclear@26 339
nuclear@26 340 METHODDEF(void)
nuclear@26 341 null_method (j_compress_ptr cinfo)
nuclear@26 342 {
nuclear@26 343 /* no work needed */
nuclear@26 344 }
nuclear@26 345
nuclear@26 346
nuclear@26 347 /*
nuclear@26 348 * Module initialization routine for input colorspace conversion.
nuclear@26 349 */
nuclear@26 350
nuclear@26 351 GLOBAL(void)
nuclear@26 352 jinit_color_converter (j_compress_ptr cinfo)
nuclear@26 353 {
nuclear@26 354 my_cconvert_ptr cconvert;
nuclear@26 355
nuclear@26 356 cconvert = (my_cconvert_ptr)
nuclear@26 357 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@26 358 SIZEOF(my_color_converter));
nuclear@26 359 cinfo->cconvert = (struct jpeg_color_converter *) cconvert;
nuclear@26 360 /* set start_pass to null method until we find out differently */
nuclear@26 361 cconvert->pub.start_pass = null_method;
nuclear@26 362
nuclear@26 363 /* Make sure input_components agrees with in_color_space */
nuclear@26 364 switch (cinfo->in_color_space) {
nuclear@26 365 case JCS_GRAYSCALE:
nuclear@26 366 if (cinfo->input_components != 1)
nuclear@26 367 ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
nuclear@26 368 break;
nuclear@26 369
nuclear@26 370 case JCS_RGB:
nuclear@26 371 #if RGB_PIXELSIZE != 3
nuclear@26 372 if (cinfo->input_components != RGB_PIXELSIZE)
nuclear@26 373 ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
nuclear@26 374 break;
nuclear@26 375 #endif /* else share code with YCbCr */
nuclear@26 376
nuclear@26 377 case JCS_YCbCr:
nuclear@26 378 if (cinfo->input_components != 3)
nuclear@26 379 ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
nuclear@26 380 break;
nuclear@26 381
nuclear@26 382 case JCS_CMYK:
nuclear@26 383 case JCS_YCCK:
nuclear@26 384 if (cinfo->input_components != 4)
nuclear@26 385 ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
nuclear@26 386 break;
nuclear@26 387
nuclear@26 388 default: /* JCS_UNKNOWN can be anything */
nuclear@26 389 if (cinfo->input_components < 1)
nuclear@26 390 ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE);
nuclear@26 391 break;
nuclear@26 392 }
nuclear@26 393
nuclear@26 394 /* Check num_components, set conversion method based on requested space */
nuclear@26 395 switch (cinfo->jpeg_color_space) {
nuclear@26 396 case JCS_GRAYSCALE:
nuclear@26 397 if (cinfo->num_components != 1)
nuclear@26 398 ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
nuclear@26 399 if (cinfo->in_color_space == JCS_GRAYSCALE)
nuclear@26 400 cconvert->pub.color_convert = grayscale_convert;
nuclear@26 401 else if (cinfo->in_color_space == JCS_RGB) {
nuclear@26 402 cconvert->pub.start_pass = rgb_ycc_start;
nuclear@26 403 cconvert->pub.color_convert = rgb_gray_convert;
nuclear@26 404 } else if (cinfo->in_color_space == JCS_YCbCr)
nuclear@26 405 cconvert->pub.color_convert = grayscale_convert;
nuclear@26 406 else
nuclear@26 407 ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
nuclear@26 408 break;
nuclear@26 409
nuclear@26 410 case JCS_RGB:
nuclear@26 411 if (cinfo->num_components != 3)
nuclear@26 412 ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
nuclear@26 413 if (cinfo->in_color_space == JCS_RGB && RGB_PIXELSIZE == 3)
nuclear@26 414 cconvert->pub.color_convert = null_convert;
nuclear@26 415 else
nuclear@26 416 ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
nuclear@26 417 break;
nuclear@26 418
nuclear@26 419 case JCS_YCbCr:
nuclear@26 420 if (cinfo->num_components != 3)
nuclear@26 421 ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
nuclear@26 422 if (cinfo->in_color_space == JCS_RGB) {
nuclear@26 423 cconvert->pub.start_pass = rgb_ycc_start;
nuclear@26 424 cconvert->pub.color_convert = rgb_ycc_convert;
nuclear@26 425 } else if (cinfo->in_color_space == JCS_YCbCr)
nuclear@26 426 cconvert->pub.color_convert = null_convert;
nuclear@26 427 else
nuclear@26 428 ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
nuclear@26 429 break;
nuclear@26 430
nuclear@26 431 case JCS_CMYK:
nuclear@26 432 if (cinfo->num_components != 4)
nuclear@26 433 ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
nuclear@26 434 if (cinfo->in_color_space == JCS_CMYK)
nuclear@26 435 cconvert->pub.color_convert = null_convert;
nuclear@26 436 else
nuclear@26 437 ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
nuclear@26 438 break;
nuclear@26 439
nuclear@26 440 case JCS_YCCK:
nuclear@26 441 if (cinfo->num_components != 4)
nuclear@26 442 ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
nuclear@26 443 if (cinfo->in_color_space == JCS_CMYK) {
nuclear@26 444 cconvert->pub.start_pass = rgb_ycc_start;
nuclear@26 445 cconvert->pub.color_convert = cmyk_ycck_convert;
nuclear@26 446 } else if (cinfo->in_color_space == JCS_YCCK)
nuclear@26 447 cconvert->pub.color_convert = null_convert;
nuclear@26 448 else
nuclear@26 449 ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
nuclear@26 450 break;
nuclear@26 451
nuclear@26 452 default: /* allow null conversion of JCS_UNKNOWN */
nuclear@26 453 if (cinfo->jpeg_color_space != cinfo->in_color_space ||
nuclear@26 454 cinfo->num_components != cinfo->input_components)
nuclear@26 455 ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
nuclear@26 456 cconvert->pub.color_convert = null_convert;
nuclear@26 457 break;
nuclear@26 458 }
nuclear@26 459 }