*
*
* 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:
#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)
{
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