720 lines
22 KiB
C
720 lines
22 KiB
C
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/*
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* jdcolor.c
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*
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* Copyright (C) 1991-1997, Thomas G. Lane.
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* Modified 2011-2019 by Guido Vollbeding.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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*
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* This file contains output colorspace conversion routines.
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*/
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#define JPEG_INTERNALS
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#include "jinclude.h"
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#include "jpeglib.h"
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#if RANGE_BITS < 2
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/* Deliberate syntax err */
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Sorry, this code requires 2 or more range extension bits.
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#endif
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/* Private subobject */
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typedef struct {
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struct jpeg_color_deconverter pub; /* public fields */
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/* Private state for YCbCr->RGB and BG_YCC->RGB conversion */
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int * Cr_r_tab; /* => table for Cr to R conversion */
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int * Cb_b_tab; /* => table for Cb to B conversion */
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INT32 * Cr_g_tab; /* => table for Cr to G conversion */
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INT32 * Cb_g_tab; /* => table for Cb to G conversion */
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/* Private state for RGB->Y conversion */
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INT32 * rgb_y_tab; /* => table for RGB to Y conversion */
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} my_color_deconverter;
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typedef my_color_deconverter * my_cconvert_ptr;
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/*************** YCbCr -> RGB conversion: most common case **************/
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/*************** BG_YCC -> RGB conversion: less common case **************/
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/*************** RGB -> Y conversion: less common case **************/
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/*
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* YCbCr is defined per Recommendation ITU-R BT.601-7 (03/2011),
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* previously known as Recommendation CCIR 601-1, except that Cb and Cr
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* are normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5.
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* sRGB (standard RGB color space) is defined per IEC 61966-2-1:1999.
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* sYCC (standard luma-chroma-chroma color space with extended gamut)
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* is defined per IEC 61966-2-1:1999 Amendment A1:2003 Annex F.
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* bg-sRGB and bg-sYCC (big gamut standard color spaces)
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* are defined per IEC 61966-2-1:1999 Amendment A1:2003 Annex G.
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* Note that the derived conversion coefficients given in some of these
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* documents are imprecise. The general conversion equations are
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*
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* R = Y + K * (1 - Kr) * Cr
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* G = Y - K * (Kb * (1 - Kb) * Cb + Kr * (1 - Kr) * Cr) / (1 - Kr - Kb)
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* B = Y + K * (1 - Kb) * Cb
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*
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* Y = Kr * R + (1 - Kr - Kb) * G + Kb * B
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*
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* With Kr = 0.299 and Kb = 0.114 (derived according to SMPTE RP 177-1993
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* from the 1953 FCC NTSC primaries and CIE Illuminant C), K = 2 for sYCC,
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* the conversion equations to be implemented are therefore
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*
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* R = Y + 1.402 * Cr
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* G = Y - 0.344136286 * Cb - 0.714136286 * Cr
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* B = Y + 1.772 * Cb
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*
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* Y = 0.299 * R + 0.587 * G + 0.114 * B
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*
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* where Cb and Cr represent the incoming values less CENTERJSAMPLE.
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* For bg-sYCC, with K = 4, the equations are
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*
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* R = Y + 2.804 * Cr
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* G = Y - 0.688272572 * Cb - 1.428272572 * Cr
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* B = Y + 3.544 * Cb
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*
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* To avoid floating-point arithmetic, we represent the fractional constants
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* as integers scaled up by 2^16 (about 4 digits precision); we have to divide
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* the products by 2^16, with appropriate rounding, to get the correct answer.
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* Notice that Y, being an integral input, does not contribute any fraction
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* so it need not participate in the rounding.
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*
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* For even more speed, we avoid doing any multiplications in the inner loop
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* by precalculating the constants times Cb and Cr for all possible values.
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* For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table);
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* for 9-bit to 12-bit samples it is still acceptable. It's not very
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* reasonable for 16-bit samples, but if you want lossless storage you
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* shouldn't be changing colorspace anyway.
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* The Cr=>R and Cb=>B values can be rounded to integers in advance; the
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* values for the G calculation are left scaled up, since we must add them
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* together before rounding.
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*/
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#define SCALEBITS 16 /* speediest right-shift on some machines */
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#define ONE_HALF ((INT32) 1 << (SCALEBITS-1))
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#define FIX(x) ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
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/* We allocate one big table for RGB->Y conversion and divide it up into
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* three parts, instead of doing three alloc_small requests. This lets us
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* use a single table base address, which can be held in a register in the
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* inner loops on many machines (more than can hold all three addresses,
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* anyway).
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*/
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#define R_Y_OFF 0 /* offset to R => Y section */
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#define G_Y_OFF (1*(MAXJSAMPLE+1)) /* offset to G => Y section */
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#define B_Y_OFF (2*(MAXJSAMPLE+1)) /* etc. */
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#define TABLE_SIZE (3*(MAXJSAMPLE+1))
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/*
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* Initialize tables for YCbCr->RGB and BG_YCC->RGB colorspace conversion.
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*/
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LOCAL(void)
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build_ycc_rgb_table (j_decompress_ptr cinfo)
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/* Normal case, sYCC */
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{
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my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
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int i;
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INT32 x;
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SHIFT_TEMPS
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cconvert->Cr_r_tab = (int *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(int));
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cconvert->Cb_b_tab = (int *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(int));
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cconvert->Cr_g_tab = (INT32 *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(INT32));
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cconvert->Cb_g_tab = (INT32 *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(INT32));
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for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
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/* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
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/* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
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/* Cr=>R value is nearest int to 1.402 * x */
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cconvert->Cr_r_tab[i] = (int) DESCALE(FIX(1.402) * x, SCALEBITS);
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/* Cb=>B value is nearest int to 1.772 * x */
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cconvert->Cb_b_tab[i] = (int) DESCALE(FIX(1.772) * x, SCALEBITS);
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/* Cr=>G value is scaled-up -0.714136286 * x */
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cconvert->Cr_g_tab[i] = (- FIX(0.714136286)) * x;
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/* Cb=>G value is scaled-up -0.344136286 * x */
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/* We also add in ONE_HALF so that need not do it in inner loop */
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cconvert->Cb_g_tab[i] = (- FIX(0.344136286)) * x + ONE_HALF;
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}
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}
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LOCAL(void)
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build_bg_ycc_rgb_table (j_decompress_ptr cinfo)
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/* Wide gamut case, bg-sYCC */
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{
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my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
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int i;
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INT32 x;
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SHIFT_TEMPS
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cconvert->Cr_r_tab = (int *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(int));
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cconvert->Cb_b_tab = (int *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(int));
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cconvert->Cr_g_tab = (INT32 *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(INT32));
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cconvert->Cb_g_tab = (INT32 *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE+1) * SIZEOF(INT32));
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for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
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/* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
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/* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
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/* Cr=>R value is nearest int to 2.804 * x */
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cconvert->Cr_r_tab[i] = (int) DESCALE(FIX(2.804) * x, SCALEBITS);
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/* Cb=>B value is nearest int to 3.544 * x */
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cconvert->Cb_b_tab[i] = (int) DESCALE(FIX(3.544) * x, SCALEBITS);
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/* Cr=>G value is scaled-up -1.428272572 * x */
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cconvert->Cr_g_tab[i] = (- FIX(1.428272572)) * x;
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/* Cb=>G value is scaled-up -0.688272572 * x */
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/* We also add in ONE_HALF so that need not do it in inner loop */
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cconvert->Cb_g_tab[i] = (- FIX(0.688272572)) * x + ONE_HALF;
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}
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}
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/*
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* Convert some rows of samples to the output colorspace.
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*
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* Note that we change from noninterleaved, one-plane-per-component format
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* to interleaved-pixel format. The output buffer is therefore three times
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* as wide as the input buffer.
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*
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* A starting row offset is provided only for the input buffer. The caller
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* can easily adjust the passed output_buf value to accommodate any row
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* offset required on that side.
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*/
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METHODDEF(void)
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ycc_rgb_convert (j_decompress_ptr cinfo,
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JSAMPIMAGE input_buf, JDIMENSION input_row,
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JSAMPARRAY output_buf, int num_rows)
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{
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my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
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register int y, cb, cr;
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register JSAMPROW outptr;
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register JSAMPROW inptr0, inptr1, inptr2;
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register JDIMENSION col;
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JDIMENSION num_cols = cinfo->output_width;
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/* copy these pointers into registers if possible */
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register JSAMPLE * range_limit = cinfo->sample_range_limit;
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register int * Crrtab = cconvert->Cr_r_tab;
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register int * Cbbtab = cconvert->Cb_b_tab;
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register INT32 * Crgtab = cconvert->Cr_g_tab;
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register INT32 * Cbgtab = cconvert->Cb_g_tab;
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SHIFT_TEMPS
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while (--num_rows >= 0) {
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inptr0 = input_buf[0][input_row];
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inptr1 = input_buf[1][input_row];
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inptr2 = input_buf[2][input_row];
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input_row++;
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outptr = *output_buf++;
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for (col = 0; col < num_cols; col++) {
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y = GETJSAMPLE(inptr0[col]);
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cb = GETJSAMPLE(inptr1[col]);
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cr = GETJSAMPLE(inptr2[col]);
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/* Range-limiting is essential due to noise introduced by DCT losses,
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* for extended gamut (sYCC) and wide gamut (bg-sYCC) encodings.
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*/
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outptr[RGB_RED] = range_limit[y + Crrtab[cr]];
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outptr[RGB_GREEN] = range_limit[y +
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((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
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SCALEBITS))];
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outptr[RGB_BLUE] = range_limit[y + Cbbtab[cb]];
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outptr += RGB_PIXELSIZE;
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}
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}
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}
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/**************** Cases other than YCC -> RGB ****************/
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/*
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* Initialize for RGB->grayscale colorspace conversion.
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*/
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LOCAL(void)
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build_rgb_y_table (j_decompress_ptr cinfo)
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{
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my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
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INT32 * rgb_y_tab;
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INT32 i;
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/* Allocate and fill in the conversion tables. */
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cconvert->rgb_y_tab = rgb_y_tab = (INT32 *) (*cinfo->mem->alloc_small)
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((j_common_ptr) cinfo, JPOOL_IMAGE, TABLE_SIZE * SIZEOF(INT32));
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for (i = 0; i <= MAXJSAMPLE; i++) {
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rgb_y_tab[i+R_Y_OFF] = FIX(0.299) * i;
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rgb_y_tab[i+G_Y_OFF] = FIX(0.587) * i;
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rgb_y_tab[i+B_Y_OFF] = FIX(0.114) * i + ONE_HALF;
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}
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}
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/*
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* Convert RGB to grayscale.
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*/
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METHODDEF(void)
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rgb_gray_convert (j_decompress_ptr cinfo,
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JSAMPIMAGE input_buf, JDIMENSION input_row,
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JSAMPARRAY output_buf, int num_rows)
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{
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my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
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register int r, g, b;
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register INT32 * ctab = cconvert->rgb_y_tab;
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register JSAMPROW outptr;
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register JSAMPROW inptr0, inptr1, inptr2;
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register JDIMENSION col;
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JDIMENSION num_cols = cinfo->output_width;
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while (--num_rows >= 0) {
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inptr0 = input_buf[0][input_row];
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inptr1 = input_buf[1][input_row];
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inptr2 = input_buf[2][input_row];
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input_row++;
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outptr = *output_buf++;
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for (col = 0; col < num_cols; col++) {
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r = GETJSAMPLE(inptr0[col]);
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g = GETJSAMPLE(inptr1[col]);
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b = GETJSAMPLE(inptr2[col]);
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/* Y */
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outptr[col] = (JSAMPLE)
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((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
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>> SCALEBITS);
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}
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}
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}
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/*
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* Convert some rows of samples to the output colorspace.
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* [R-G,G,B-G] to [R,G,B] conversion with modulo calculation
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* (inverse color transform).
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* This can be seen as an adaption of the general YCbCr->RGB
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* conversion equation with Kr = Kb = 0, while replacing the
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* normalization by modulo calculation.
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*/
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METHODDEF(void)
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rgb1_rgb_convert (j_decompress_ptr cinfo,
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JSAMPIMAGE input_buf, JDIMENSION input_row,
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JSAMPARRAY output_buf, int num_rows)
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{
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register int r, g, b;
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register JSAMPROW outptr;
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register JSAMPROW inptr0, inptr1, inptr2;
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register JDIMENSION col;
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JDIMENSION num_cols = cinfo->output_width;
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||
|
|
|
||
|
|
while (--num_rows >= 0) {
|
||
|
|
inptr0 = input_buf[0][input_row];
|
||
|
|
inptr1 = input_buf[1][input_row];
|
||
|
|
inptr2 = input_buf[2][input_row];
|
||
|
|
input_row++;
|
||
|
|
outptr = *output_buf++;
|
||
|
|
for (col = 0; col < num_cols; col++) {
|
||
|
|
r = GETJSAMPLE(inptr0[col]);
|
||
|
|
g = GETJSAMPLE(inptr1[col]);
|
||
|
|
b = GETJSAMPLE(inptr2[col]);
|
||
|
|
/* Assume that MAXJSAMPLE+1 is a power of 2, so that the MOD
|
||
|
|
* (modulo) operator is equivalent to the bitmask operator AND.
|
||
|
|
*/
|
||
|
|
outptr[RGB_RED] = (JSAMPLE) ((r + g - CENTERJSAMPLE) & MAXJSAMPLE);
|
||
|
|
outptr[RGB_GREEN] = (JSAMPLE) g;
|
||
|
|
outptr[RGB_BLUE] = (JSAMPLE) ((b + g - CENTERJSAMPLE) & MAXJSAMPLE);
|
||
|
|
outptr += RGB_PIXELSIZE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* [R-G,G,B-G] to grayscale conversion with modulo calculation
|
||
|
|
* (inverse color transform).
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
rgb1_gray_convert (j_decompress_ptr cinfo,
|
||
|
|
JSAMPIMAGE input_buf, JDIMENSION input_row,
|
||
|
|
JSAMPARRAY output_buf, int num_rows)
|
||
|
|
{
|
||
|
|
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
|
||
|
|
register int r, g, b;
|
||
|
|
register INT32 * ctab = cconvert->rgb_y_tab;
|
||
|
|
register JSAMPROW outptr;
|
||
|
|
register JSAMPROW inptr0, inptr1, inptr2;
|
||
|
|
register JDIMENSION col;
|
||
|
|
JDIMENSION num_cols = cinfo->output_width;
|
||
|
|
|
||
|
|
while (--num_rows >= 0) {
|
||
|
|
inptr0 = input_buf[0][input_row];
|
||
|
|
inptr1 = input_buf[1][input_row];
|
||
|
|
inptr2 = input_buf[2][input_row];
|
||
|
|
input_row++;
|
||
|
|
outptr = *output_buf++;
|
||
|
|
for (col = 0; col < num_cols; col++) {
|
||
|
|
r = GETJSAMPLE(inptr0[col]);
|
||
|
|
g = GETJSAMPLE(inptr1[col]);
|
||
|
|
b = GETJSAMPLE(inptr2[col]);
|
||
|
|
/* Assume that MAXJSAMPLE+1 is a power of 2, so that the MOD
|
||
|
|
* (modulo) operator is equivalent to the bitmask operator AND.
|
||
|
|
*/
|
||
|
|
r = (r + g - CENTERJSAMPLE) & MAXJSAMPLE;
|
||
|
|
b = (b + g - CENTERJSAMPLE) & MAXJSAMPLE;
|
||
|
|
/* Y */
|
||
|
|
outptr[col] = (JSAMPLE)
|
||
|
|
((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF])
|
||
|
|
>> SCALEBITS);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Convert some rows of samples to the output colorspace.
|
||
|
|
* No colorspace change, but conversion from separate-planes
|
||
|
|
* to interleaved representation.
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
rgb_convert (j_decompress_ptr cinfo,
|
||
|
|
JSAMPIMAGE input_buf, JDIMENSION input_row,
|
||
|
|
JSAMPARRAY output_buf, int num_rows)
|
||
|
|
{
|
||
|
|
register JSAMPROW outptr;
|
||
|
|
register JSAMPROW inptr0, inptr1, inptr2;
|
||
|
|
register JDIMENSION col;
|
||
|
|
JDIMENSION num_cols = cinfo->output_width;
|
||
|
|
|
||
|
|
while (--num_rows >= 0) {
|
||
|
|
inptr0 = input_buf[0][input_row];
|
||
|
|
inptr1 = input_buf[1][input_row];
|
||
|
|
inptr2 = input_buf[2][input_row];
|
||
|
|
input_row++;
|
||
|
|
outptr = *output_buf++;
|
||
|
|
for (col = 0; col < num_cols; col++) {
|
||
|
|
/* We can dispense with GETJSAMPLE() here */
|
||
|
|
outptr[RGB_RED] = inptr0[col];
|
||
|
|
outptr[RGB_GREEN] = inptr1[col];
|
||
|
|
outptr[RGB_BLUE] = inptr2[col];
|
||
|
|
outptr += RGB_PIXELSIZE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Color conversion for no colorspace change: just copy the data,
|
||
|
|
* converting from separate-planes to interleaved representation.
|
||
|
|
* We assume out_color_components == num_components.
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
null_convert (j_decompress_ptr cinfo,
|
||
|
|
JSAMPIMAGE input_buf, JDIMENSION input_row,
|
||
|
|
JSAMPARRAY output_buf, int num_rows)
|
||
|
|
{
|
||
|
|
register JSAMPROW outptr;
|
||
|
|
register JSAMPROW inptr;
|
||
|
|
register JDIMENSION count;
|
||
|
|
register int num_comps = cinfo->num_components;
|
||
|
|
JDIMENSION num_cols = cinfo->output_width;
|
||
|
|
int ci;
|
||
|
|
|
||
|
|
while (--num_rows >= 0) {
|
||
|
|
/* It seems fastest to make a separate pass for each component. */
|
||
|
|
for (ci = 0; ci < num_comps; ci++) {
|
||
|
|
inptr = input_buf[ci][input_row];
|
||
|
|
outptr = output_buf[0] + ci;
|
||
|
|
for (count = num_cols; count > 0; count--) {
|
||
|
|
*outptr = *inptr++; /* don't need GETJSAMPLE() here */
|
||
|
|
outptr += num_comps;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
input_row++;
|
||
|
|
output_buf++;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Color conversion for grayscale: just copy the data.
|
||
|
|
* This also works for YCC -> grayscale conversion, in which
|
||
|
|
* we just copy the Y (luminance) component and ignore chrominance.
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
grayscale_convert (j_decompress_ptr cinfo,
|
||
|
|
JSAMPIMAGE input_buf, JDIMENSION input_row,
|
||
|
|
JSAMPARRAY output_buf, int num_rows)
|
||
|
|
{
|
||
|
|
jcopy_sample_rows(input_buf[0], (int) input_row, output_buf, 0,
|
||
|
|
num_rows, cinfo->output_width);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Convert grayscale to RGB: just duplicate the graylevel three times.
|
||
|
|
* This is provided to support applications that don't want to cope
|
||
|
|
* with grayscale as a separate case.
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
gray_rgb_convert (j_decompress_ptr cinfo,
|
||
|
|
JSAMPIMAGE input_buf, JDIMENSION input_row,
|
||
|
|
JSAMPARRAY output_buf, int num_rows)
|
||
|
|
{
|
||
|
|
register JSAMPROW outptr;
|
||
|
|
register JSAMPROW inptr;
|
||
|
|
register JDIMENSION col;
|
||
|
|
JDIMENSION num_cols = cinfo->output_width;
|
||
|
|
|
||
|
|
while (--num_rows >= 0) {
|
||
|
|
inptr = input_buf[0][input_row++];
|
||
|
|
outptr = *output_buf++;
|
||
|
|
for (col = 0; col < num_cols; col++) {
|
||
|
|
/* We can dispense with GETJSAMPLE() here */
|
||
|
|
outptr[RGB_RED] = outptr[RGB_GREEN] = outptr[RGB_BLUE] = inptr[col];
|
||
|
|
outptr += RGB_PIXELSIZE;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Convert some rows of samples to the output colorspace.
|
||
|
|
* This version handles Adobe-style YCCK->CMYK conversion,
|
||
|
|
* where we convert YCbCr to R=1-C, G=1-M, and B=1-Y using the
|
||
|
|
* same conversion as above, while passing K (black) unchanged.
|
||
|
|
* We assume build_ycc_rgb_table has been called.
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
ycck_cmyk_convert (j_decompress_ptr cinfo,
|
||
|
|
JSAMPIMAGE input_buf, JDIMENSION input_row,
|
||
|
|
JSAMPARRAY output_buf, int num_rows)
|
||
|
|
{
|
||
|
|
my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert;
|
||
|
|
register int y, cb, cr;
|
||
|
|
register JSAMPROW outptr;
|
||
|
|
register JSAMPROW inptr0, inptr1, inptr2, inptr3;
|
||
|
|
register JDIMENSION col;
|
||
|
|
JDIMENSION num_cols = cinfo->output_width;
|
||
|
|
/* copy these pointers into registers if possible */
|
||
|
|
register JSAMPLE * range_limit = cinfo->sample_range_limit;
|
||
|
|
register int * Crrtab = cconvert->Cr_r_tab;
|
||
|
|
register int * Cbbtab = cconvert->Cb_b_tab;
|
||
|
|
register INT32 * Crgtab = cconvert->Cr_g_tab;
|
||
|
|
register INT32 * Cbgtab = cconvert->Cb_g_tab;
|
||
|
|
SHIFT_TEMPS
|
||
|
|
|
||
|
|
while (--num_rows >= 0) {
|
||
|
|
inptr0 = input_buf[0][input_row];
|
||
|
|
inptr1 = input_buf[1][input_row];
|
||
|
|
inptr2 = input_buf[2][input_row];
|
||
|
|
inptr3 = input_buf[3][input_row];
|
||
|
|
input_row++;
|
||
|
|
outptr = *output_buf++;
|
||
|
|
for (col = 0; col < num_cols; col++) {
|
||
|
|
y = GETJSAMPLE(inptr0[col]);
|
||
|
|
cb = GETJSAMPLE(inptr1[col]);
|
||
|
|
cr = GETJSAMPLE(inptr2[col]);
|
||
|
|
/* Range-limiting is essential due to noise introduced by DCT losses,
|
||
|
|
* and for extended gamut encodings (sYCC).
|
||
|
|
*/
|
||
|
|
outptr[0] = range_limit[MAXJSAMPLE - (y + Crrtab[cr])]; /* red */
|
||
|
|
outptr[1] = range_limit[MAXJSAMPLE - (y + /* green */
|
||
|
|
((int) RIGHT_SHIFT(Cbgtab[cb] + Crgtab[cr],
|
||
|
|
SCALEBITS)))];
|
||
|
|
outptr[2] = range_limit[MAXJSAMPLE - (y + Cbbtab[cb])]; /* blue */
|
||
|
|
/* K passes through unchanged */
|
||
|
|
outptr[3] = inptr3[col]; /* don't need GETJSAMPLE here */
|
||
|
|
outptr += 4;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Empty method for start_pass.
|
||
|
|
*/
|
||
|
|
|
||
|
|
METHODDEF(void)
|
||
|
|
start_pass_dcolor (j_decompress_ptr cinfo)
|
||
|
|
{
|
||
|
|
/* no work needed */
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Module initialization routine for output colorspace conversion.
|
||
|
|
*/
|
||
|
|
|
||
|
|
GLOBAL(void)
|
||
|
|
jinit_color_deconverter (j_decompress_ptr cinfo)
|
||
|
|
{
|
||
|
|
my_cconvert_ptr cconvert;
|
||
|
|
int ci;
|
||
|
|
|
||
|
|
cconvert = (my_cconvert_ptr) (*cinfo->mem->alloc_small)
|
||
|
|
((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(my_color_deconverter));
|
||
|
|
cinfo->cconvert = &cconvert->pub;
|
||
|
|
cconvert->pub.start_pass = start_pass_dcolor;
|
||
|
|
|
||
|
|
/* Make sure num_components agrees with jpeg_color_space */
|
||
|
|
switch (cinfo->jpeg_color_space) {
|
||
|
|
case JCS_GRAYSCALE:
|
||
|
|
if (cinfo->num_components != 1)
|
||
|
|
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case JCS_RGB:
|
||
|
|
case JCS_YCbCr:
|
||
|
|
case JCS_BG_RGB:
|
||
|
|
case JCS_BG_YCC:
|
||
|
|
if (cinfo->num_components != 3)
|
||
|
|
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
|
||
|
|
break;
|
||
|
|
|
||
|
|
case JCS_CMYK:
|
||
|
|
case JCS_YCCK:
|
||
|
|
if (cinfo->num_components != 4)
|
||
|
|
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
|
||
|
|
break;
|
||
|
|
|
||
|
|
default: /* JCS_UNKNOWN can be anything */
|
||
|
|
if (cinfo->num_components < 1)
|
||
|
|
ERREXIT(cinfo, JERR_BAD_J_COLORSPACE);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Support color transform only for RGB colorspaces */
|
||
|
|
if (cinfo->color_transform &&
|
||
|
|
cinfo->jpeg_color_space != JCS_RGB &&
|
||
|
|
cinfo->jpeg_color_space != JCS_BG_RGB)
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
|
||
|
|
/* Set out_color_components and conversion method based on requested space.
|
||
|
|
* Also clear the component_needed flags for any unused components,
|
||
|
|
* so that earlier pipeline stages can avoid useless computation.
|
||
|
|
*/
|
||
|
|
|
||
|
|
switch (cinfo->out_color_space) {
|
||
|
|
case JCS_GRAYSCALE:
|
||
|
|
cinfo->out_color_components = 1;
|
||
|
|
switch (cinfo->jpeg_color_space) {
|
||
|
|
case JCS_GRAYSCALE:
|
||
|
|
case JCS_YCbCr:
|
||
|
|
case JCS_BG_YCC:
|
||
|
|
cconvert->pub.color_convert = grayscale_convert;
|
||
|
|
/* For color->grayscale conversion, only the Y (0) component is needed */
|
||
|
|
for (ci = 1; ci < cinfo->num_components; ci++)
|
||
|
|
cinfo->comp_info[ci].component_needed = FALSE;
|
||
|
|
break;
|
||
|
|
case JCS_RGB:
|
||
|
|
switch (cinfo->color_transform) {
|
||
|
|
case JCT_NONE:
|
||
|
|
cconvert->pub.color_convert = rgb_gray_convert;
|
||
|
|
break;
|
||
|
|
case JCT_SUBTRACT_GREEN:
|
||
|
|
cconvert->pub.color_convert = rgb1_gray_convert;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
}
|
||
|
|
build_rgb_y_table(cinfo);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case JCS_RGB:
|
||
|
|
cinfo->out_color_components = RGB_PIXELSIZE;
|
||
|
|
switch (cinfo->jpeg_color_space) {
|
||
|
|
case JCS_GRAYSCALE:
|
||
|
|
cconvert->pub.color_convert = gray_rgb_convert;
|
||
|
|
break;
|
||
|
|
case JCS_YCbCr:
|
||
|
|
cconvert->pub.color_convert = ycc_rgb_convert;
|
||
|
|
build_ycc_rgb_table(cinfo);
|
||
|
|
break;
|
||
|
|
case JCS_BG_YCC:
|
||
|
|
cconvert->pub.color_convert = ycc_rgb_convert;
|
||
|
|
build_bg_ycc_rgb_table(cinfo);
|
||
|
|
break;
|
||
|
|
case JCS_RGB:
|
||
|
|
switch (cinfo->color_transform) {
|
||
|
|
case JCT_NONE:
|
||
|
|
cconvert->pub.color_convert = rgb_convert;
|
||
|
|
break;
|
||
|
|
case JCT_SUBTRACT_GREEN:
|
||
|
|
cconvert->pub.color_convert = rgb1_rgb_convert;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case JCS_BG_RGB:
|
||
|
|
cinfo->out_color_components = RGB_PIXELSIZE;
|
||
|
|
if (cinfo->jpeg_color_space != JCS_BG_RGB)
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
switch (cinfo->color_transform) {
|
||
|
|
case JCT_NONE:
|
||
|
|
cconvert->pub.color_convert = rgb_convert;
|
||
|
|
break;
|
||
|
|
case JCT_SUBTRACT_GREEN:
|
||
|
|
cconvert->pub.color_convert = rgb1_rgb_convert;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
case JCS_CMYK:
|
||
|
|
cinfo->out_color_components = 4;
|
||
|
|
switch (cinfo->jpeg_color_space) {
|
||
|
|
case JCS_YCCK:
|
||
|
|
cconvert->pub.color_convert = ycck_cmyk_convert;
|
||
|
|
build_ycc_rgb_table(cinfo);
|
||
|
|
break;
|
||
|
|
case JCS_CMYK:
|
||
|
|
cconvert->pub.color_convert = null_convert;
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
}
|
||
|
|
break;
|
||
|
|
|
||
|
|
default: /* permit null conversion to same output space */
|
||
|
|
if (cinfo->out_color_space != cinfo->jpeg_color_space)
|
||
|
|
/* unsupported non-null conversion */
|
||
|
|
ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL);
|
||
|
|
cinfo->out_color_components = cinfo->num_components;
|
||
|
|
cconvert->pub.color_convert = null_convert;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (cinfo->quantize_colors)
|
||
|
|
cinfo->output_components = 1; /* single colormapped output component */
|
||
|
|
else
|
||
|
|
cinfo->output_components = cinfo->out_color_components;
|
||
|
|
}
|