X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=images%2Fcolor.h;h=a148e6c3c062b38e1e4ec5159fc133ec6ef7e167;hb=09e7fe5641b94148d998a1b620bf694f353cb17b;hp=ec3cd4afd99e928f88baef9f8bafa3a0712d3d5c;hpb=6e052a5a07718b9f0ff417b27adf8b8ed8903f36;p=libucw.git diff --git a/images/color.h b/images/color.h index ec3cd4af..a148e6c3 100644 --- a/images/color.h +++ b/images/color.h @@ -8,6 +8,8 @@ * * * 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: @@ -23,9 +25,127 @@ #ifndef _IMAGES_COLOR_H #define _IMAGES_COLOR_H +#include "images/images.h" + +/* 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 uns 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(uns id); +uns color_space_name_to_id(byte *name); + +/* Struct color manipulation */ +int color_get(struct color *color, byte *src, uns src_space); +int color_put(struct image_context *ctx, struct color *color, byte *dest, uns dest_space); + +static inline void +color_make_gray(struct color *color, uns gray) +{ + color->c[0] = gray; + color->color_space = COLOR_SPACE_GRAYSCALE; +} + +static inline void +color_make_rgb(struct color *color, uns r, uns g, uns 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 { + uns 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 uns +rgb_to_gray_func(uns r, uns g, uns b) +{ + return (r * 19660 + g * 38666 + b * 7210) >> 16; +} + /* Exact slow conversion routines */ -void srgb_to_xyz_slow(double dest[3], double src[3]); -void xyz_to_luv_slow(double dest[3], double src[3]); +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