Workshop o mikrokontrolérech na SKSP 2024.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

298 lines
10 KiB

/*
* Image Library -- Color Spaces
*
* (c) 2006 Pavel Charvat <pchar@ucw.cz>
*
* This software may be freely distributed and used according to the terms
* of the GNU Lesser General Public License.
*
*
* References:
* - A Review of RGB Color Spaces, Danny Pascale (2003)
* - http://www.adobe.com/digitalimag/pdfs/AdobeRGB1998.pdf
* - http://www.tecgraf.puc-rio.br/~mgattass/color/ColorIndex.html
*
* FIXME:
* - fix theoretical problems with rounding errors in srgb_to_luv_pixel()
* - SIMD should help to speed up conversion of large arrays
* - maybe try to generate a long switch in color_conv_pixel()
* with optimized entries instead of access to interpolation table
* - most of multiplications in srgb_to_luv_pixels can be replaced
* with tables lookup... tests shows almost the same speed for random
* input and cca 40% gain when input colors fit in CPU chache
*/
#ifndef _IMAGES_COLOR_H
#define _IMAGES_COLOR_H
#include <images/images.h>
#ifdef CONFIG_UCW_CLEAN_ABI
#define cmyk_to_rgb_exact ucw_cmyk_to_rgb_exact
#define color_adobe_rgb_info ucw_color_adobe_rgb_info
#define color_apple_rgb_info ucw_color_apple_rgb_info
#define color_black ucw_color_black
#define color_cie_rgb_info ucw_color_cie_rgb_info
#define color_color_match_rgb_info ucw_color_color_match_rgb_info
#define color_compute_bradford_matrix ucw_color_compute_bradford_matrix
#define color_compute_color_space_to_xyz_matrix ucw_color_compute_color_space_to_xyz_matrix
#define color_compute_color_spaces_conversion_matrix ucw_color_compute_color_spaces_conversion_matrix
#define color_conv_init ucw_color_conv_init
#define color_conv_pixels ucw_color_conv_pixels
#define color_get ucw_color_get
#define color_illuminant_d50 ucw_color_illuminant_d50
#define color_illuminant_d65 ucw_color_illuminant_d65
#define color_illuminant_e ucw_color_illuminant_e
#define color_interpolation_table ucw_color_interpolation_table
#define color_invert_matrix ucw_color_invert_matrix
#define color_put ucw_color_put
#define color_space_channels ucw_color_space_channels
#define color_space_id_to_name ucw_color_space_id_to_name
#define color_space_name ucw_color_space_name
#define color_space_name_to_id ucw_color_space_name_to_id
#define color_srgb_info ucw_color_srgb_info
#define color_white ucw_color_white
#define image_conv ucw_image_conv
#define image_conv_defaults ucw_image_conv_defaults
#define luv_to_xyz_exact ucw_luv_to_xyz_exact
#define rgb_to_cmyk_exact ucw_rgb_to_cmyk_exact
#define srgb_to_luv_grid ucw_srgb_to_luv_grid
#define srgb_to_luv_init ucw_srgb_to_luv_init
#define srgb_to_luv_pixels ucw_srgb_to_luv_pixels
#define srgb_to_luv_tab1 ucw_srgb_to_luv_tab1
#define srgb_to_luv_tab2 ucw_srgb_to_luv_tab2
#define srgb_to_luv_tab3 ucw_srgb_to_luv_tab3
#define srgb_to_xyz_exact ucw_srgb_to_xyz_exact
#define xyz_to_luv_exact ucw_xyz_to_luv_exact
#define xyz_to_srgb_exact ucw_xyz_to_srgb_exact
#endif
/* Basic color spaces */
enum {
COLOR_SPACE_UNKNOWN = 0,
COLOR_SPACE_UNKNOWN_1 = 1, /* unknown 1-channel color space */
COLOR_SPACE_UNKNOWN_2 = 2, /* unknown 2-channels color space */
COLOR_SPACE_UNKNOWN_3 = 3, /* unknown 3-channels color space */
COLOR_SPACE_UNKNOWN_4 = 4, /* unknown 4-channels color space */
COLOR_SPACE_UNKNOWN_MAX = 4,
COLOR_SPACE_GRAYSCALE,
COLOR_SPACE_RGB,
COLOR_SPACE_XYZ,
COLOR_SPACE_LAB,
COLOR_SPACE_LUV,
COLOR_SPACE_YCBCR,
COLOR_SPACE_CMYK,
COLOR_SPACE_YCCK,
COLOR_SPACE_MAX
};
extern uint color_space_channels[COLOR_SPACE_MAX];
extern byte *color_space_name[COLOR_SPACE_MAX];
/* Color space ID <-> name conversions */
byte *color_space_id_to_name(uint id);
uint color_space_name_to_id(byte *name);
/* Struct color manipulation */
int color_get(struct color *color, byte *src, uint src_space);
int color_put(struct image_context *ctx, struct color *color, byte *dest, uint dest_space);
static inline void color_make_gray(struct color *color, uint gray)
{
color->c[0] = gray;
color->color_space = COLOR_SPACE_GRAYSCALE;
}
static inline void color_make_rgb(struct color *color, uint r, uint g, uint b)
{
color->c[0] = r;
color->c[1] = g;
color->c[2] = b;
color->color_space = COLOR_SPACE_RGB;
}
extern struct color color_black, color_white;
/* Conversion between various pixel formats */
enum {
IMAGE_CONV_FILL_ALPHA = 1,
IMAGE_CONV_COPY_ALPHA = 2,
IMAGE_CONV_APPLY_ALPHA = 4,
};
struct image_conv_options {
uint flags;
struct color background;
};
extern struct image_conv_options image_conv_defaults;
int image_conv(struct image_context *ctx, struct image *dest, struct image *src, struct image_conv_options *opt);
/* Color spaces in the CIE 1931 chromacity diagram */
struct color_space_chromacity_info {
double prim1[2];
double prim2[2];
double prim3[2];
double white[2];
};
struct color_space_gamma_info {
double simple_gamma;
double detailed_gamma;
double offset;
double transition;
double slope;
};
struct color_space_info {
byte *name;
struct color_space_chromacity_info chromacity;
struct color_space_gamma_info gamma;
};
extern const double
color_illuminant_d50[2],
color_illuminant_d65[2],
color_illuminant_e[2];
extern const struct color_space_info
color_adobe_rgb_info, /* Adobe RGB (1998) */
color_apple_rgb_info, /* Apple RGB */
color_cie_rgb_info, /* CIE RGB */
color_color_match_rgb_info, /* ColorMatch RGB */
color_srgb_info; /* sRGB */
/* These routines do not check numeric errors! */
void color_compute_color_space_to_xyz_matrix(double matrix[9], const struct color_space_chromacity_info *space);
void color_compute_bradford_matrix(double matrix[9], const double src[2], const double dest[2]);
void color_compute_color_spaces_conversion_matrix(double matrix[9], const struct color_space_chromacity_info *src, const struct color_space_chromacity_info *dest);
void color_invert_matrix(double dest[9], double matrix[9]);
static inline uint rgb_to_gray_func(uint r, uint g, uint b)
{
return (r * 19660 + g * 38666 + b * 7210) >> 16;
}
/* Exact slow conversion routines */
void srgb_to_xyz_exact(double dest[3], double src[3]);
void xyz_to_srgb_exact(double dest[3], double src[3]);
void xyz_to_luv_exact(double dest[3], double src[3]);
void luv_to_xyz_exact(double dest[3], double src[3]);
void rgb_to_cmyk_exact(double dest[4], double src[3]);
void cmyk_to_rgb_exact(double dest[3], double src[4]);
/* Reference white */
#define REF_WHITE_X 0.96422
#define REF_WHITE_Y 1.
#define REF_WHITE_Z 0.82521
/* sRGB -> XYZ matrix */
#define SRGB_XYZ_XR 0.412424
#define SRGB_XYZ_XG 0.357579
#define SRGB_XYZ_XB 0.180464
#define SRGB_XYZ_YR 0.212656
#define SRGB_XYZ_YG 0.715158
#define SRGB_XYZ_YB 0.072186
#define SRGB_XYZ_ZR 0.019332
#define SRGB_XYZ_ZG 0.119193
#define SRGB_XYZ_ZB 0.950444
/*********************** OPTIMIZED CONVERSION ROUTINES **********************/
/* sRGB -> Luv parameters */
#define SRGB_TO_LUV_TAB2_SIZE 9
#define SRGB_TO_LUV_TAB2_SCALE 11
#define SRGB_TO_LUV_TAB3_SIZE 8
#define SRGB_TO_LUV_TAB3_SCALE (39 - SRGB_TO_LUV_TAB2_SCALE - SRGB_TO_LUV_TAB3_SIZE)
extern u16 srgb_to_luv_tab1[256];
extern u16 srgb_to_luv_tab2[9 << SRGB_TO_LUV_TAB2_SIZE];
extern u32 srgb_to_luv_tab3[20 << SRGB_TO_LUV_TAB3_SIZE];
void srgb_to_luv_init(void);
void srgb_to_luv_pixels(byte *dest, byte *src, uint count);
/* L covers the interval [0..255]; u and v are centered to 128 and scaled by 1/4 in respect of L */
static inline void srgb_to_luv_pixel(byte *dest, byte *src)
{
uint r = srgb_to_luv_tab1[src[0]];
uint g = srgb_to_luv_tab1[src[1]];
uint b = srgb_to_luv_tab1[src[2]];
uint x =
(uint)(4 * SRGB_XYZ_XR * 0xffff) * r +
(uint)(4 * SRGB_XYZ_XG * 0xffff) * g +
(uint)(4 * SRGB_XYZ_XB * 0xffff) * b;
uint y =
(uint)(9 * SRGB_XYZ_YR * 0xffff) * r +
(uint)(9 * SRGB_XYZ_YG * 0xffff) * g +
(uint)(9 * SRGB_XYZ_YB * 0xffff) * b;
uint l = srgb_to_luv_tab2[y >> (28 - SRGB_TO_LUV_TAB2_SIZE)];
dest[0] = l >> (SRGB_TO_LUV_TAB2_SCALE - 8);
uint sum =
(uint)((SRGB_XYZ_XR + 15 * SRGB_XYZ_YR + 3 * SRGB_XYZ_ZR) * 0x7fff) * r +
(uint)((SRGB_XYZ_XG + 15 * SRGB_XYZ_YG + 3 * SRGB_XYZ_ZG) * 0x7fff) * g +
(uint)((SRGB_XYZ_XB + 15 * SRGB_XYZ_YB + 3 * SRGB_XYZ_ZB) * 0x7fff) * b;
uint s = srgb_to_luv_tab3[sum >> (27 - SRGB_TO_LUV_TAB3_SIZE)];
int xs = ((u64)x * s) >> 32;
int ys = ((u64)y * s) >> 32;
int xw = ((4 * 13) << (SRGB_TO_LUV_TAB3_SCALE - 4)) *
REF_WHITE_X / (REF_WHITE_X + 15 * REF_WHITE_Y + 3 * REF_WHITE_Z);
int yw = ((9 * 13) << (SRGB_TO_LUV_TAB3_SCALE - 4)) *
REF_WHITE_Y / (REF_WHITE_X + 15 * REF_WHITE_Y + 3 * REF_WHITE_Z);
int u = (int)(l) * (xs - xw);
int v = (int)(l) * (ys - yw);
dest[1] = 128 + (u >> (SRGB_TO_LUV_TAB3_SCALE + SRGB_TO_LUV_TAB2_SCALE - 10));
dest[2] = 128 + (v >> (SRGB_TO_LUV_TAB3_SCALE + SRGB_TO_LUV_TAB2_SCALE - 10));
}
/****************** GENERAL INTERPOLATION IN 3D GRID ********************/
#define COLOR_CONV_SIZE 5 /* 128K conversion grid size */
#define COLOR_CONV_OFS 3 /* 8K interpolation table size */
struct color_grid_node {
byte val[4];
};
struct color_interpolation_node {
u16 ofs[4];
u16 mul[4];
};
extern struct color_grid_node *srgb_to_luv_grid;
extern struct color_interpolation_node *color_interpolation_table;
void color_conv_init(void);
void color_conv_pixels(byte *dest, byte *src, uint count, struct color_grid_node *grid);
#define COLOR_CONV_SCALE_CONST (((((1 << COLOR_CONV_SIZE) - 1) << 16) + (1 << (16 - COLOR_CONV_OFS))) / 255)
static inline void color_conv_pixel(byte *dest, byte *src, struct color_grid_node *grid)
{
uint s0 = src[0] * COLOR_CONV_SCALE_CONST;
uint s1 = src[1] * COLOR_CONV_SCALE_CONST;
uint s2 = src[2] * COLOR_CONV_SCALE_CONST;
struct color_grid_node *g0, *g1, *g2, *g3, *g = grid +
((s0 >> 16) + ((s1 >> 16) << COLOR_CONV_SIZE) + ((s2 >> 16) << (2 * COLOR_CONV_SIZE)));
struct color_interpolation_node *n = color_interpolation_table +
(((s0 & (0x10000 - (0x10000 >> COLOR_CONV_OFS))) >> (16 - COLOR_CONV_OFS)) +
((s1 & (0x10000 - (0x10000 >> COLOR_CONV_OFS))) >> (16 - 2 * COLOR_CONV_OFS)) +
((s2 & (0x10000 - (0x10000 >> COLOR_CONV_OFS))) >> (16 - 3 * COLOR_CONV_OFS)));
g0 = g + n->ofs[0];
g1 = g + n->ofs[1];
g2 = g + n->ofs[2];
g3 = g + n->ofs[3];
dest[0] = (g0->val[0] * n->mul[0] + g1->val[0] * n->mul[1] +
g2->val[0] * n->mul[2] + g3->val[0] * n->mul[3] + 128) >> 8;
dest[1] = (g0->val[1] * n->mul[0] + g1->val[1] * n->mul[1] +
g2->val[1] * n->mul[2] + g3->val[1] * n->mul[3] + 128) >> 8;
dest[2] = (g0->val[2] * n->mul[0] + g1->val[2] * n->mul[1] +
g2->val[2] * n->mul[2] + g3->val[2] * n->mul[3] + 128) >> 8;
}
#endif