*
*
* 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:
#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