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