diff --git a/misc/colorspace-tools.h b/misc/colorspace-tools.h index 8a2f871..7950fba 100644 --- a/misc/colorspace-tools.h +++ b/misc/colorspace-tools.h @@ -75,7 +75,7 @@ vec3 XYZtoSRGB(vec3 XYZ) return XYZ * m; } - vec3 RGBtoYUV(vec3 RGB) +vec3 RGBtoYUV(vec3 RGB) { const mat3x3 m = mat3x3( 0.2126, 0.7152, 0.0722, @@ -85,7 +85,7 @@ vec3 XYZtoSRGB(vec3 XYZ) return RGB * m; } - vec3 YUVtoRGB(vec3 YUV) +vec3 YUVtoRGB(vec3 YUV) { const mat3x3 m = mat3x3( 1.000, 0.000, 1.28033, @@ -124,7 +124,7 @@ vec3 XYZtoYxy(vec3 XYZ) return Yxy; } - vec3 YxytoXYZ(vec3 Yxy) +vec3 YxytoXYZ(vec3 Yxy) { vec3 XYZ; XYZ.g = Yxy.r; @@ -134,7 +134,30 @@ vec3 XYZtoYxy(vec3 XYZ) return XYZ; } - // Converting pure hue to RGB +// RGB <-> CMYK conversions require 4 channels +vec4 RGBtoCMYK(vec3 RGB){ + float Red = RGB.r; + float Green = RGB.g; + float Blue = RGB.b; + float Black = min(1.0 - Red, min(1.0 - Green, 1.0 - Blue)); + float Cyan = (1.0 - Red - Black) / (1.0 - Black); + float Magenta = (1.0 - Green - Black) / (1.0 - Black); + float Yellow = (1.0 - Blue - Black) / (1.0 - Black); + return vec4(Cyan, Magenta, Yellow, Black); +} + +vec3 CMYKtoRGB(vec4 CMYK){ + float Cyan = CMYK.x; + float Magenta = CMYK.y; + float Yellow = CMYK.z; + float Black = CMYK.w; + float Red = 1.0 - min(1.0, Cyan * (1.0 - Black) + Black); + float Green = 1.0 - min(1.0, Magenta * (1.0 - Black) + Black); + float Blue = 1.0 - min(1.0, Yellow * (1.0 - Black) + Black); + return vec3(Red, Green, Blue); +} + +// Converting pure hue to RGB vec3 HUEtoRGB(float H) { float R = abs(H * 6.0 - 3.0) - 1.0; @@ -182,14 +205,14 @@ vec3 HSVtoRGB(vec3 c) } // conversion from NTSC RGB Reference White D65 ( color space used by NA/Japan TV's ) to XYZ - vec3 NTSC(vec3 c) +vec3 NTSC(vec3 c) { vec3 v = vec3(pow(c.r, 2.2), pow(c.g, 2.2), pow(c.b, 2.2)); //Inverse Companding return RGBtoXYZ(v); } - // conversion from XYZ to sRGB Reference White D65 ( color space used by windows ) - vec3 sRGB(vec3 c) +// conversion from XYZ to sRGB Reference White D65 ( color space used by windows ) +vec3 sRGB(vec3 c) { vec3 v = XYZtoSRGB(c); v = DecodeGamma(v, 2.4); //Companding @@ -197,8 +220,8 @@ vec3 HSVtoRGB(vec3 c) return v; } - // NTSC RGB to sRGB - vec3 NTSCtoSRGB( vec3 c ) +// NTSC RGB to sRGB +vec3 NTSCtoSRGB( vec3 c ) { return sRGB(NTSC( c )); }