X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=images%2Fcolor.h;h=8c87e87c5414500d89a77bdb603e9a21dd5943c3;hb=26b9fc31aa816c2c5eaa2f5b10d8a988e4d11cf0;hp=8ec18e92c92e2a38cc04a664a1880289b8cfca21;hpb=422234aee83909200561bcce45f6bc1ed84f4789;p=libucw.git diff --git a/images/color.h b/images/color.h index 8ec18e92..8c87e87c 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: @@ -25,6 +27,60 @@ #include "images/images.h" +// A comparison of four multimedia RGB spaces, Danny Pascale + +enum { + COLOR_SPACE_UNKNOWN = 0, + COLOR_SPACE_GRAYSCALE, + COLOR_SPACE_RGB, + COLOR_SPACE_XYZ, + COLOR_SPACE_LAB, + COLOR_SPACE_LUV, + COLOR_SPACE_YCBCR, + COLOR_SPACE_MAX +}; + +/* 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) { @@ -49,13 +105,15 @@ color_make_rgb(struct color *color, uns r, uns g, uns b) color->color_space = COLOR_SPACE_RGB; } -void color_put_color_space(byte *dest, struct color *color, enum color_space color_space); +void color_put_color_space(byte *dest, struct color *color, uns color_space); void color_put_grayscale(byte *dest, struct color *color); void color_put_rgb(byte *dest, struct color *color); /* 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]); /* Reference white */ #define REF_WHITE_X 0.96422