/* * jccolor.c * * This file was part of the Independent JPEG Group's software: * Copyright (C) 1991-1996, Thomas G. Lane. * Modifications: * Copyright 2009 Pierre Ossman for Cendio AB * Copyright (C) 2009-2012, D. R. Commander. * For conditions of distribution and use, see the accompanying README file. * * This file contains input colorspace conversion routines. */ #define JPEG_INTERNALS #include "jinclude.h" #include "jpeglib.h" #include "jsimd.h" #include "config.h" /* Private subobject */ typedef struct { struct jpeg_color_converter pub; /* public fields */ /* Private state for RGB->YCC conversion */ INT32 * rgb_ycc_tab; /* => table for RGB to YCbCr conversion */ } my_color_converter; typedef my_color_converter * my_cconvert_ptr; /**************** RGB -> YCbCr conversion: most common case **************/ /* * YCbCr is defined per CCIR 601-1, except that Cb and Cr are * normalized to the range 0..MAXJSAMPLE rather than -0.5 .. 0.5. * The conversion equations to be implemented are therefore * Y = 0.29900 * R + 0.58700 * G + 0.11400 * B * Cb = -0.16874 * R - 0.33126 * G + 0.50000 * B + CENTERJSAMPLE * Cr = 0.50000 * R - 0.41869 * G - 0.08131 * B + CENTERJSAMPLE * (These numbers are derived from TIFF 6.0 section 21, dated 3-June-92.) * Note: older versions of the IJG code used a zero offset of MAXJSAMPLE/2, * rather than CENTERJSAMPLE, for Cb and Cr. This gave equal positive and * negative swings for Cb/Cr, but meant that grayscale values (Cb=Cr=0) * were not represented exactly. Now we sacrifice exact representation of * maximum red and maximum blue in order to get exact grayscales. * * To avoid floating-point arithmetic, we represent the fractional constants * as integers scaled up by 2^16 (about 4 digits precision); we have to divide * the products by 2^16, with appropriate rounding, to get the correct answer. * * For even more speed, we avoid doing any multiplications in the inner loop * by precalculating the constants times R,G,B for all possible values. * For 8-bit JSAMPLEs this is very reasonable (only 256 entries per table); * for 12-bit samples it is still acceptable. It's not very reasonable for * 16-bit samples, but if you want lossless storage you shouldn't be changing * colorspace anyway. * The CENTERJSAMPLE offsets and the rounding fudge-factor of 0.5 are included * in the tables to save adding them separately in the inner loop. */ #define SCALEBITS 16 /* speediest right-shift on some machines */ #define CBCR_OFFSET ((INT32) CENTERJSAMPLE << SCALEBITS) #define ONE_HALF ((INT32) 1 << (SCALEBITS-1)) #define FIX(x) ((INT32) ((x) * (1L< Y section */ #define G_Y_OFF (1*(MAXJSAMPLE+1)) /* offset to G => Y section */ #define B_Y_OFF (2*(MAXJSAMPLE+1)) /* etc. */ #define R_CB_OFF (3*(MAXJSAMPLE+1)) #define G_CB_OFF (4*(MAXJSAMPLE+1)) #define B_CB_OFF (5*(MAXJSAMPLE+1)) #define R_CR_OFF B_CB_OFF /* B=>Cb, R=>Cr are the same */ #define G_CR_OFF (6*(MAXJSAMPLE+1)) #define B_CR_OFF (7*(MAXJSAMPLE+1)) #define TABLE_SIZE (8*(MAXJSAMPLE+1)) /* Include inline routines for colorspace extensions */ #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #define RGB_RED EXT_RGB_RED #define RGB_GREEN EXT_RGB_GREEN #define RGB_BLUE EXT_RGB_BLUE #define RGB_PIXELSIZE EXT_RGB_PIXELSIZE #define rgb_ycc_convert_internal extrgb_ycc_convert_internal #define rgb_gray_convert_internal extrgb_gray_convert_internal #define rgb_rgb_convert_internal extrgb_rgb_convert_internal #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef rgb_ycc_convert_internal #undef rgb_gray_convert_internal #undef rgb_rgb_convert_internal #define RGB_RED EXT_RGBX_RED #define RGB_GREEN EXT_RGBX_GREEN #define RGB_BLUE EXT_RGBX_BLUE #define RGB_PIXELSIZE EXT_RGBX_PIXELSIZE #define rgb_ycc_convert_internal extrgbx_ycc_convert_internal #define rgb_gray_convert_internal extrgbx_gray_convert_internal #define rgb_rgb_convert_internal extrgbx_rgb_convert_internal #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef rgb_ycc_convert_internal #undef rgb_gray_convert_internal #undef rgb_rgb_convert_internal #define RGB_RED EXT_BGR_RED #define RGB_GREEN EXT_BGR_GREEN #define RGB_BLUE EXT_BGR_BLUE #define RGB_PIXELSIZE EXT_BGR_PIXELSIZE #define rgb_ycc_convert_internal extbgr_ycc_convert_internal #define rgb_gray_convert_internal extbgr_gray_convert_internal #define rgb_rgb_convert_internal extbgr_rgb_convert_internal #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef rgb_ycc_convert_internal #undef rgb_gray_convert_internal #undef rgb_rgb_convert_internal #define RGB_RED EXT_BGRX_RED #define RGB_GREEN EXT_BGRX_GREEN #define RGB_BLUE EXT_BGRX_BLUE #define RGB_PIXELSIZE EXT_BGRX_PIXELSIZE #define rgb_ycc_convert_internal extbgrx_ycc_convert_internal #define rgb_gray_convert_internal extbgrx_gray_convert_internal #define rgb_rgb_convert_internal extbgrx_rgb_convert_internal #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef rgb_ycc_convert_internal #undef rgb_gray_convert_internal #undef rgb_rgb_convert_internal #define RGB_RED EXT_XBGR_RED #define RGB_GREEN EXT_XBGR_GREEN #define RGB_BLUE EXT_XBGR_BLUE #define RGB_PIXELSIZE EXT_XBGR_PIXELSIZE #define rgb_ycc_convert_internal extxbgr_ycc_convert_internal #define rgb_gray_convert_internal extxbgr_gray_convert_internal #define rgb_rgb_convert_internal extxbgr_rgb_convert_internal #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef rgb_ycc_convert_internal #undef rgb_gray_convert_internal #undef rgb_rgb_convert_internal #define RGB_RED EXT_XRGB_RED #define RGB_GREEN EXT_XRGB_GREEN #define RGB_BLUE EXT_XRGB_BLUE #define RGB_PIXELSIZE EXT_XRGB_PIXELSIZE #define rgb_ycc_convert_internal extxrgb_ycc_convert_internal #define rgb_gray_convert_internal extxrgb_gray_convert_internal #define rgb_rgb_convert_internal extxrgb_rgb_convert_internal #include "jccolext.h" #undef RGB_RED #undef RGB_GREEN #undef RGB_BLUE #undef RGB_PIXELSIZE #undef rgb_ycc_convert_internal #undef rgb_gray_convert_internal #undef rgb_rgb_convert_internal /* * Initialize for RGB->YCC colorspace conversion. */ METHODDEF(void) rgb_ycc_start (j_compress_ptr cinfo) { my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert; INT32 * rgb_ycc_tab; INT32 i; /* Allocate and fill in the conversion tables. */ cconvert->rgb_ycc_tab = rgb_ycc_tab = (INT32 *) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, (TABLE_SIZE * SIZEOF(INT32))); for (i = 0; i <= MAXJSAMPLE; i++) { rgb_ycc_tab[i+R_Y_OFF] = FIX(0.29900) * i; rgb_ycc_tab[i+G_Y_OFF] = FIX(0.58700) * i; rgb_ycc_tab[i+B_Y_OFF] = FIX(0.11400) * i + ONE_HALF; rgb_ycc_tab[i+R_CB_OFF] = (-FIX(0.16874)) * i; rgb_ycc_tab[i+G_CB_OFF] = (-FIX(0.33126)) * i; /* We use a rounding fudge-factor of 0.5-epsilon for Cb and Cr. * This ensures that the maximum output will round to MAXJSAMPLE * not MAXJSAMPLE+1, and thus that we don't have to range-limit. */ rgb_ycc_tab[i+B_CB_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1; /* B=>Cb and R=>Cr tables are the same rgb_ycc_tab[i+R_CR_OFF] = FIX(0.50000) * i + CBCR_OFFSET + ONE_HALF-1; */ rgb_ycc_tab[i+G_CR_OFF] = (-FIX(0.41869)) * i; rgb_ycc_tab[i+B_CR_OFF] = (-FIX(0.08131)) * i; } } /* * Convert some rows of samples to the JPEG colorspace. */ METHODDEF(void) rgb_ycc_convert (j_compress_ptr cinfo, JSAMPARRAY input_buf, JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows) { switch (cinfo->in_color_space) { case JCS_EXT_RGB: extrgb_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_RGBX: case JCS_EXT_RGBA: extrgbx_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_BGR: extbgr_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_BGRX: case JCS_EXT_BGRA: extbgrx_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_XBGR: case JCS_EXT_ABGR: extxbgr_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_XRGB: case JCS_EXT_ARGB: extxrgb_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; default: rgb_ycc_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; } } /**************** Cases other than RGB -> YCbCr **************/ /* * Convert some rows of samples to the JPEG colorspace. */ METHODDEF(void) rgb_gray_convert (j_compress_ptr cinfo, JSAMPARRAY input_buf, JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows) { switch (cinfo->in_color_space) { case JCS_EXT_RGB: extrgb_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_RGBX: case JCS_EXT_RGBA: extrgbx_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_BGR: extbgr_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_BGRX: case JCS_EXT_BGRA: extbgrx_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_XBGR: case JCS_EXT_ABGR: extxbgr_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_XRGB: case JCS_EXT_ARGB: extxrgb_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; default: rgb_gray_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; } } /* * Extended RGB to plain RGB conversion */ METHODDEF(void) rgb_rgb_convert (j_compress_ptr cinfo, JSAMPARRAY input_buf, JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows) { switch (cinfo->in_color_space) { case JCS_EXT_RGB: extrgb_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_RGBX: case JCS_EXT_RGBA: extrgbx_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_BGR: extbgr_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_BGRX: case JCS_EXT_BGRA: extbgrx_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_XBGR: case JCS_EXT_ABGR: extxbgr_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; case JCS_EXT_XRGB: case JCS_EXT_ARGB: extxrgb_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; default: rgb_rgb_convert_internal(cinfo, input_buf, output_buf, output_row, num_rows); break; } } /* * Convert some rows of samples to the JPEG colorspace. * This version handles Adobe-style CMYK->YCCK conversion, * where we convert R=1-C, G=1-M, and B=1-Y to YCbCr using the same * conversion as above, while passing K (black) unchanged. * We assume rgb_ycc_start has been called. */ METHODDEF(void) cmyk_ycck_convert (j_compress_ptr cinfo, JSAMPARRAY input_buf, JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows) { my_cconvert_ptr cconvert = (my_cconvert_ptr) cinfo->cconvert; register int r, g, b; register INT32 * ctab = cconvert->rgb_ycc_tab; register JSAMPROW inptr; register JSAMPROW outptr0, outptr1, outptr2, outptr3; register JDIMENSION col; JDIMENSION num_cols = cinfo->image_width; while (--num_rows >= 0) { inptr = *input_buf++; outptr0 = output_buf[0][output_row]; outptr1 = output_buf[1][output_row]; outptr2 = output_buf[2][output_row]; outptr3 = output_buf[3][output_row]; output_row++; for (col = 0; col < num_cols; col++) { r = MAXJSAMPLE - GETJSAMPLE(inptr[0]); g = MAXJSAMPLE - GETJSAMPLE(inptr[1]); b = MAXJSAMPLE - GETJSAMPLE(inptr[2]); /* K passes through as-is */ outptr3[col] = inptr[3]; /* don't need GETJSAMPLE here */ inptr += 4; /* If the inputs are 0..MAXJSAMPLE, the outputs of these equations * must be too; we do not need an explicit range-limiting operation. * Hence the value being shifted is never negative, and we don't * need the general RIGHT_SHIFT macro. */ /* Y */ outptr0[col] = (JSAMPLE) ((ctab[r+R_Y_OFF] + ctab[g+G_Y_OFF] + ctab[b+B_Y_OFF]) >> SCALEBITS); /* Cb */ outptr1[col] = (JSAMPLE) ((ctab[r+R_CB_OFF] + ctab[g+G_CB_OFF] + ctab[b+B_CB_OFF]) >> SCALEBITS); /* Cr */ outptr2[col] = (JSAMPLE) ((ctab[r+R_CR_OFF] + ctab[g+G_CR_OFF] + ctab[b+B_CR_OFF]) >> SCALEBITS); } } } /* * Convert some rows of samples to the JPEG colorspace. * This version handles grayscale output with no conversion. * The source can be either plain grayscale or YCbCr (since Y == gray). */ METHODDEF(void) grayscale_convert (j_compress_ptr cinfo, JSAMPARRAY input_buf, JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows) { register JSAMPROW inptr; register JSAMPROW outptr; register JDIMENSION col; JDIMENSION num_cols = cinfo->image_width; int instride = cinfo->input_components; while (--num_rows >= 0) { inptr = *input_buf++; outptr = output_buf[0][output_row]; output_row++; for (col = 0; col < num_cols; col++) { outptr[col] = inptr[0]; /* don't need GETJSAMPLE() here */ inptr += instride; } } } /* * Convert some rows of samples to the JPEG colorspace. * This version handles multi-component colorspaces without conversion. * We assume input_components == num_components. */ METHODDEF(void) null_convert (j_compress_ptr cinfo, JSAMPARRAY input_buf, JSAMPIMAGE output_buf, JDIMENSION output_row, int num_rows) { register JSAMPROW inptr; register JSAMPROW outptr; register JDIMENSION col; register int ci; int nc = cinfo->num_components; JDIMENSION num_cols = cinfo->image_width; while (--num_rows >= 0) { /* It seems fastest to make a separate pass for each component. */ for (ci = 0; ci < nc; ci++) { inptr = *input_buf; outptr = output_buf[ci][output_row]; for (col = 0; col < num_cols; col++) { outptr[col] = inptr[ci]; /* don't need GETJSAMPLE() here */ inptr += nc; } } input_buf++; output_row++; } } /* * Empty method for start_pass. */ METHODDEF(void) null_method (j_compress_ptr cinfo) { /* no work needed */ } /* * Module initialization routine for input colorspace conversion. */ GLOBAL(void) jinit_color_converter (j_compress_ptr cinfo) { my_cconvert_ptr cconvert; cconvert = (my_cconvert_ptr) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, SIZEOF(my_color_converter)); cinfo->cconvert = (struct jpeg_color_converter *) cconvert; /* set start_pass to null method until we find out differently */ cconvert->pub.start_pass = null_method; /* Make sure input_components agrees with in_color_space */ switch (cinfo->in_color_space) { case JCS_GRAYSCALE: if (cinfo->input_components != 1) ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); break; case JCS_RGB: case JCS_EXT_RGB: case JCS_EXT_RGBX: case JCS_EXT_BGR: case JCS_EXT_BGRX: case JCS_EXT_XBGR: case JCS_EXT_XRGB: case JCS_EXT_RGBA: case JCS_EXT_BGRA: case JCS_EXT_ABGR: case JCS_EXT_ARGB: if (cinfo->input_components != rgb_pixelsize[cinfo->in_color_space]) ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); break; case JCS_YCbCr: if (cinfo->input_components != 3) ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); break; case JCS_CMYK: case JCS_YCCK: if (cinfo->input_components != 4) ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); break; default: /* JCS_UNKNOWN can be anything */ if (cinfo->input_components < 1) ERREXIT(cinfo, JERR_BAD_IN_COLORSPACE); break; } /* Check num_components, set conversion method based on requested space */ switch (cinfo->jpeg_color_space) { case JCS_GRAYSCALE: if (cinfo->num_components != 1) ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); if (cinfo->in_color_space == JCS_GRAYSCALE) cconvert->pub.color_convert = grayscale_convert; else if (cinfo->in_color_space == JCS_RGB || cinfo->in_color_space == JCS_EXT_RGB || cinfo->in_color_space == JCS_EXT_RGBX || cinfo->in_color_space == JCS_EXT_BGR || cinfo->in_color_space == JCS_EXT_BGRX || cinfo->in_color_space == JCS_EXT_XBGR || cinfo->in_color_space == JCS_EXT_XRGB || cinfo->in_color_space == JCS_EXT_RGBA || cinfo->in_color_space == JCS_EXT_BGRA || cinfo->in_color_space == JCS_EXT_ABGR || cinfo->in_color_space == JCS_EXT_ARGB) { if (jsimd_can_rgb_gray()) cconvert->pub.color_convert = jsimd_rgb_gray_convert; else { cconvert->pub.start_pass = rgb_ycc_start; cconvert->pub.color_convert = rgb_gray_convert; } } else if (cinfo->in_color_space == JCS_YCbCr) cconvert->pub.color_convert = grayscale_convert; else ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL); break; case JCS_RGB: if (cinfo->num_components != 3) ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); if (rgb_red[cinfo->in_color_space] == 0 && rgb_green[cinfo->in_color_space] == 1 && rgb_blue[cinfo->in_color_space] == 2 && rgb_pixelsize[cinfo->in_color_space] == 3) cconvert->pub.color_convert = null_convert; else if (cinfo->in_color_space == JCS_RGB || cinfo->in_color_space == JCS_EXT_RGB || cinfo->in_color_space == JCS_EXT_RGBX || cinfo->in_color_space == JCS_EXT_BGR || cinfo->in_color_space == JCS_EXT_BGRX || cinfo->in_color_space == JCS_EXT_XBGR || cinfo->in_color_space == JCS_EXT_XRGB || cinfo->in_color_space == JCS_EXT_RGBA || cinfo->in_color_space == JCS_EXT_BGRA || cinfo->in_color_space == JCS_EXT_ABGR || cinfo->in_color_space == JCS_EXT_ARGB) cconvert->pub.color_convert = rgb_rgb_convert; else ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL); break; case JCS_YCbCr: if (cinfo->num_components != 3) ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); if (cinfo->in_color_space == JCS_RGB || cinfo->in_color_space == JCS_EXT_RGB || cinfo->in_color_space == JCS_EXT_RGBX || cinfo->in_color_space == JCS_EXT_BGR || cinfo->in_color_space == JCS_EXT_BGRX || cinfo->in_color_space == JCS_EXT_XBGR || cinfo->in_color_space == JCS_EXT_XRGB || cinfo->in_color_space == JCS_EXT_RGBA || cinfo->in_color_space == JCS_EXT_BGRA || cinfo->in_color_space == JCS_EXT_ABGR || cinfo->in_color_space == JCS_EXT_ARGB) { if (jsimd_can_rgb_ycc()) cconvert->pub.color_convert = jsimd_rgb_ycc_convert; else { cconvert->pub.start_pass = rgb_ycc_start; cconvert->pub.color_convert = rgb_ycc_convert; } } else if (cinfo->in_color_space == JCS_YCbCr) cconvert->pub.color_convert = null_convert; else ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL); break; case JCS_CMYK: if (cinfo->num_components != 4) ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); if (cinfo->in_color_space == JCS_CMYK) cconvert->pub.color_convert = null_convert; else ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL); break; case JCS_YCCK: if (cinfo->num_components != 4) ERREXIT(cinfo, JERR_BAD_J_COLORSPACE); if (cinfo->in_color_space == JCS_CMYK) { cconvert->pub.start_pass = rgb_ycc_start; cconvert->pub.color_convert = cmyk_ycck_convert; } else if (cinfo->in_color_space == JCS_YCCK) cconvert->pub.color_convert = null_convert; else ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL); break; default: /* allow null conversion of JCS_UNKNOWN */ if (cinfo->jpeg_color_space != cinfo->in_color_space || cinfo->num_components != cinfo->input_components) ERREXIT(cinfo, JERR_CONVERSION_NOTIMPL); cconvert->pub.color_convert = null_convert; break; } }