colors.js

/*
	Color conversions
	Copyright (c) 2011, Cory Nelson (phrosty@gmail.com)
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions are met:
		 * Redistributions of source code must retain the above copyright
			notice, this list of conditions and the following disclaimer.
		 * Redistributions in binary form must reproduce the above copyright
			notice, this list of conditions and the following disclaimer in the
			documentation and/or other materials provided with the distribution.

	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
	ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
	DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

	When possible, constants are given as accurate pre-computed rationals. When not,
	they are given at double precision with a comment on how to compute them.
*/

(function(){ // wrap in a function to capture variables.

function clamp(x, min, max)
{
	if(x < min) return min;
	if(x > max) return max;
	return x;
}

function clampdeg(hue)
{
	hue %= 360;

	if(hue < 0)
	{
		hue += 360;
	}

	return hue;
}

function clamprad(hue)
{
	hue %= Math.PI * 2;

	if(hue < 0)
	{
		hue += Math.PI * 2;
	}

	return hue;
}

function ColorLShuv(L, S, h, clamped)
{
	this.clamped = clamped || L < 0 || L > 100; // TODO: what is S min/max?

	this.L = clamp(L, 0, 100);
	this.S = S;
	this.h = clamprad(h);

	this.toLChuv = function()
	{
		return new ColorLChuv(this.L, this.S * this.L, this.h);
	};
}

function ColorLChuv(L, C, h, clamped)
{
	this.clamped = clamped || L < 0 || L > 100 || C < 0 || C > 7.40066582332174237e2;

	this.L = clamp(L, 0, 100);
	this.C = clamp(C, 0, 7.40066582332174237e2); // 240/316141*sqrt(950343809713)
	this.h = clamprad(h);

	this.toLShuv = function()
	{
		return new ColorLShuv(this.L, this.C / this.L, this.h, this.clamped);
	};

	this.toLuv = function()
	{
		var h = clamprad(this.h);
		return new ColorLuv(this.L, Math.cos(h) * this.C, Math.sin(h) * this.C, this.clamped);
	};
}

function ColorLuv(L, u, v, clamped)
{
	this.clamped = clamped || L < 0 || L > 100 || u < -81304600/316141 || v > 54113280/316141; // TODO: what is u max, and v min??

	this.L = clamp(L, 0, 100);
	this.u = (u < -81304600/316141) ? -81304600/316141 : u;
	this.v = (v > 54113280/316141) ? 54113280/316141 : v;

	this.toLChuv = function()
	{
		return new ColorLChuv(
			this.L,
			Math.sqrt(this.u * this.u + this.v * this.v),
			Math.atan2(this.v, this.u),
			this.clamped);
	};

	this.toXYZ = function()
	{
		var rdiv = Color.refX + Color.refY * 15 + Color.refZ * 3;
		var ur = Color.refX * 4 / rdiv;
		var vr = Color.refY * 9 / rdiv;

		if(L > 8)
		{
			var Y = (this.L + 16) / 116;
			Y = Y * Y * Y;
		}
		else
		{
			var Y = this.L * (27/24389);
		}

		var a = (this.L * 52 / (this.u + this.L * 13 * ur) - 1) / 3;
		var b = -5 * Y;
		var d = (this.L * 39 / (this.v + this.L * 13 * vr) - 5) * Y;

		var X = (d - b) / (a + 1/3);
		var Z = X * a + b;

		return new ColorXYZ(X, Y, Z, this.clamped);
	};
}

function ColorLChab(L, C, h, clamped)
{
	this.clamped = clamped || L < 0 || L > 100 || C < 0 || C > 4.64238345442629658e2;

	this.L = clamp(L, 0, 100);
	this.C = clamp(C, 0, 4.64238345442629658e2); // 2500*sqrt(1/29)
	this.h = clamprad(h);

	this.toLab = function()
	{
		var h = clamprad(this.h);
		return new ColorLab(this.L, Math.cos(h) * this.C, Math.sin(h) * this.C, this.clamped);
	};
}

function ColorLab(L, a, b, clamped)
{
	this.clamped = clamped || L < 0 || L > 100 || a < -12500/29 || a > 12500/29 || b < -5000/29 || b > 5000/29;

	this.L = clamp(L, 0, 100);
	this.a = clamp(a, -12500/29, 12500/29);
	this.b = clamp(b, -5000/29, 5000/29);

	this.toXYZ = function()
	{
		function toXYZc(c)
		{
			var c3 = c * c * c;

			if(c3 > 216 / 24389) return c3;
			return c * (108/841) - (432/24389);
		}

		var Y = (this.L + 16) / 116;

		return new ColorXYZ(
			toXYZc(Y + this.a / 500) * Color.refX,
			toXYZc(Y) * Color.refY,
			toXYZc(Y - this.b / 200) * Color.refZ,
			this.clamped);
	};

	this.toLChab = function()
	{
		return new ColorLChab(
			this.L,
			Math.sqrt(this.a * this.a + this.b * this.b),
			Math.atan2(this.b, this.a),
			this.clamped);
	};
}

function ColorxyY(x, y, Y, clamped)
{
	this.clamped = clamped || x < 0 || x > 1 || y < 0 || y > 1 || Y < 0 || Y > 1;

	this.x = clamp(x, 0, 1);
	this.y = clamp(y, 0, 1);
	this.Y = clamp(Y, 0, 1);

	this.toXYZ = function()
	{
		if(Math.abs(this.y) != 0)
		{
			var mul = this.Y / this.y;
			return new ColorXYZ(this.x * mul, this.Y, (1 - this.x - this.y) * mul);
		}
		else
		{
			return new ColorXYZ(0, 0, 0);
		}
	};
}

function ColorXYZ(X, Y, Z, clamped)
{
	this.clamped = clamped || X < 0 || X > Color.refX || Y < 0 || Y > Color.refY || Z < 0 || Z > Color.refZ;

	this.X = clamp(X, 0, Color.refX);
	this.Y = clamp(Y, 0, Color.refY);
	this.Z = clamp(Z, 0, Color.refZ);

	this.toLinearRGB = function()
	{
		return new ColorLinearRGB(
			this.X * (641589/197960)      + this.Y * (-608687/395920)    + this.Z * (-49353/98980),
			this.X * (-42591639/43944050) + this.Y * (82435961/43944050) + this.Z * (1826061/43944050),
			this.X * (49353/887015)       + this.Y * (-180961/887015)    + this.Z * (49353/46685),
			this.clamped);
	};

	this.toxyY = function()
	{
		var div = this.X + this.Y + this.Z;

		if(Math.abs(div) == 0)
		{
			div = 1;
		}

		return new ColorxyY(this.X / div, this.Y / div, this.Y, this.clamped);
	};

	this.toLab = function()
	{
		function toLabc(c)
		{
			if (c > 216 / 24389) return Math.pow(c, 1 / 3);
			return c * (841 / 108) + (4 / 49);
		}

		var X = toLabc(this.X / Color.refX);
		var Y = toLabc(this.Y / Color.refY);
		var Z = toLabc(this.Z / Color.refZ);

		return new ColorLab(116 * Y - 16, 500 * (X - Y), 200 * (Y - Z), this.clamped);
	};

	this.toLuv = function()
	{
		var rdiv = Color.refX + Color.refY * 15 + Color.refZ * 3;
		var ur = Color.refX * 4 / rdiv;
		var vr = Color.refY * 9 / rdiv;

		var div = this.X + this.Y * 15 + this.Z * 3;

		if(Math.abs(div) == 0)
		{
			div = 1;
		}

		var u = this.X * 4 / div;
		var v = this.Y * 9 / div;
		var yr = this.Y / Color.refY;

		if(yr > 216/24389)
		{
			var L = Math.pow(yr, 1 / 3) * 116 - 16;
		}
		else
		{
			var L = yr * (24389/27);
		}

		return new ColorLuv(L, L * 13 * (u - ur), L * 13 * (v - vr), this.clamped);
	};
}

function ColorLinearRGB(R, G, B, clamped)
{
	this.clamped = clamped || R < 0 || R > 1 || G < 0 || G > 1 || B < 0 || B > 1;
	this.R = clamp(R, 0, 1);
	this.G = clamp(G, 0, 1);
	this.B = clamp(B, 0, 1);

	this.toRGB = function()
	{
		function toRGBc(c)
		{
			if(c > 0.0031308) return Math.pow(c, 1 / 2.4) * 1.055 - 0.055;
			return c * 12.92;
		}

		return new ColorRGB(toRGBc(this.R), toRGBc(this.G), toRGBc(this.B), this.clamped);
	};

	this.toXYZ = function()
	{
		return new ColorXYZ(
			this.R * (5067776/12288897) + this.G * (4394405/12288897) + this.B * (4435075/24577794),
			this.R * (871024/4096299)   + this.G * (8788810/12288897) + this.B * (887015/12288897),
			this.R * (79184/4096299)    + this.G * (4394405/36866691) + this.B * (70074185/73733382),
			this.clamped);
	};
}

function ColorHSV(H, S, V, clamped)
{
	this.clamped = clamped || S < 0 || S > 1 || V < 0 || V > 1;
	this.H = clampdeg(H);
	this.S = clamp(S, 0, 1);
	this.V = clamp(V, 0, 1);

	this.toRGB = function()
	{
		if(this.S <= 0)
		{
			return new ColorRGB(this.V, this.V, this.V, this.clamped);
		}

		var H = clampdeg(this.H) / 60;
		var C = this.V * this.S;
		var m = this.V - C;
		var X = C * (1 - Math.abs(H % 2 - 1)) + m;

		C += m;

		if(H >= 5) return new ColorRGB(C, m, X, this.clamped);
		if(H >= 4) return new ColorRGB(X, m, C, this.clamped);
		if(H >= 3) return new ColorRGB(m, X, C, this.clamped);
		if(H >= 2) return new ColorRGB(m, C, X, this.clamped);
		if(H >= 1) return new ColorRGB(X, C, m, this.clamped);
		return new ColorRGB(C, X, m, this.clamped);
	};
}

function ColorHSL(H, S, L, clamped)
{
	this.clamped = clamped || S < 0 || S > 1 || L < 0 || L > 1;
	this.H = clampdeg(H);
	this.S = clamp(S, 0, 1);
	this.L = clamp(L, 0, 1);

	this.toRGB = function()
	{
		if(this.S <= 0)
		{
			return new ColorRGB(this.S, this.S, this.S, this.clamped);
		}

		var H = clampdeg(this.H) / 60;
		var C = (1 - Math.abs(this.L * 2 - 1)) * this.S;
		var m = this.L - C * 0.5;
		var X = C * (1 - Math.abs(H % 2 - 1)) + m;

		C += m;

		if(H >= 5) return new ColorRGB(C, m, X, this.clamped);
		if(H >= 4) return new ColorRGB(X, m, C, this.clamped);
		if(H >= 3) return new ColorRGB(m, X, C, this.clamped);
		if(H >= 2) return new ColorRGB(m, C, X, this.clamped);
		if(H >= 1) return new ColorRGB(X, C, m, this.clamped);
		return new ColorRGB(C, X, m, this.clamped);
	};
}

function ColorRGB(R, G, B, clamped)
{
	this.clamped = clamped || R < 0 || R > 1 || G < 0 || G > 1 || B < 0 || B > 1;
	this.R = clamp(R, 0, 1);
	this.G = clamp(G, 0, 1);
	this.B = clamp(B, 0, 1);

	this.toHSV = function()
	{
		var min = Math.min(this.R, this.G, this.B);
		var max = Math.max(this.R, this.G, this.B);
		var delta = max - min;

		if(Math.abs(delta) != 0)
		{
			var S = delta / max;

			if(max == this.R) var H = (this.G - this.B) / delta;
			else if(max == this.G) var H = (this.B - this.R) / delta + 2;
			else var H = (this.R - this.G) / delta + 4;
		}
		else
		{
			var H = 0;
			var S = 0;
		}

		return new ColorHSV(H * 60, S, max, this.clamped);
	};

	this.toHSL = function()
	{
		var min = Math.min(this.R, this.G, this.B);
		var max = Math.max(this.R, this.G, this.B);
		var delta = max - min;

		var L = (max + min) * 0.5;

		if(Math.abs(delta) != 0)
		{
			if(L < 0.5) var S = delta / (max + min);
			else var S = delta / (2 - max - min);

			if(max == this.R) var H = (this.G - this.B) / delta;
			else if(max == this.G) var H = (this.B - this.R) / delta + 2;
			else var H = (this.R - this.G) / delta + 4;
		}
		else
		{
			var H = 0;
			var S = 0;
		}

		return new ColorHSL(H * 60, S, L, this.clamped);
	};

	this.toLinearRGB = function()
	{
		function toLinearRGBc(c)
		{
			if(c > 0.04045) return Math.pow((c + 0.055) / 1.055, 2.4);
			return c / 12.92;
		}

		return new ColorLinearRGB(toLinearRGBc(this.R), toLinearRGBc(this.G), toLinearRGBc(this.B), this.clamped);
	};

	this.toYUV = function()
	{
		var mat = Color.yuvmatrix;

		var y = this.R * mat.rScale + this.G * mat.gScale + this.B * mat.bScale;
		var u = (this.B - y) / (1 - mat.bScale) * 0.5 + 0.5;
		var v = (this.R - y) / (1 - mat.rScale) * 0.5 + 0.5;

		return new ColorYUV(y, u, v, this.clamped);
	};

	this.toYIQ = function()
	{
		return new ColorYIQ(
			this.R *  0.299                + this.G *  0.587               + this.B *  0.114,
			this.R *  0.5                  + this.G * -0.23038159508364756 + this.B * -0.26961840491635244  + 0.5,
			this.R * -0.202349432337541121 + this.G *  0.5                 + this.B * -0.297650567662458879 + 0.5,
			this.clamped);
	};
}

function ColorYUV(Y, U, V, clamped)
{
	this.clamped = clamped || Y < 0 || Y > 1 || U < 0 || V > 1 || V < 0 || V > 1;
	this.Y = clamp(Y, 0, 1);
	this.U = clamp(U, 0, 1);
	this.V = clamp(V, 0, 1);

	this.toRGB = function()
	{
		var mat = Color.yuvmatrix;

		var u = (this.U - 0.5) / 0.5 * (1 - mat.bScale);
		var v = (this.V - 0.5) / 0.5 * (1 - mat.rScale);

		var r = v + this.Y;
		var b = u + this.Y;
		var g = (this.Y - r * mat.rScale - b * mat.bScale) / mat.gScale;

		return new ColorRGB(r, g, b, this.clamped);
	};
}

function ColorYIQ(Y, I, Q, clamped)
{
	this.clamped = clamped || Y < 0 || Y > 1 || I < 0 || I > 1 || Q < 0 || Q > 1;
	this.Y = clamp(Y, 0, 1);
	this.I = clamp(I, 0, 1);
	this.Q = clamp(Q, 0, 1);

	this.toRGB = function()
	{
		var i = this.I - 0.5;
		var q = this.Q - 0.5;

		return new ColorRGB(
			this.Y + i * 1.13933588212202582 - q * 0.649035964281386078,
			this.Y - i * 0.32416610079155499 + q * 0.676636193255190191,
			this.Y - i * 1.31908708412142932 - q * 1.78178677298826495,
			this.clamped);
	};
}

// CIE Delta E 1976
// JND: ~2.3
function deltaE1976(lab1, lab2)
{
	var delta_L = lab1.L - lab2.L;
	var delta_a = lab1.a - lab2.a;
	var delta_b = lab1.b - lab2.b;

	return Math.sqrt(delta_L * delta_L + delta_a * delta_a + delta_b * delta_b);
}

// CIE Delta E 1994
function deltaE1994(lab1, lab2, type)
{
	var C1 = Math.sqrt(lab1.a * lab1.a + lab1.b * lab1.b);
	var C2 = Math.sqrt(lab2.a * lab2.a + lab2.b * lab2.b);

	var delta_L = lab1.L - lab2.L;
	var delta_C = C1 - C2;
	var delta_a = lab1.a - lab2.a;
	var delta_b = lab1.b - lab2.b;
	var delta_H = Math.sqrt(delta_a * delta_a + delta_b * delta_b - delta_C * delta_C);

	if(type == 'graphic arts')
	{
		delta_C /= C1 * 0.045 + 1;
		delta_H /= C1 * 0.015 + 1;
	}
	else if(type == 'textiles')
	{
		delta_L *= 0.5;
		delta_C /= C1 * 0.048 + 1;
		delta_H /= C1 * 0.014 + 1;
	}

	return Math.sqrt(delta_L * delta_L + delta_C * delta_C + delta_H * delta_H);
}

// CIE Delta E 2000
// Note: maximum is about 158 for colors in the sRGB gamut.
function deltaE2000(lch1, lch2)
{
	var avg_L = (lch1.L + lch2.L) * 0.5;
	var delta_L = lch2.L - lch1.L;

	var avg_C = (lch1.C + lch2.C) * 0.5;
	var delta_C = lch1.C - lch2.C;

	var avg_H = (lch1.h + lch2.h) * 0.5;

	if(Math.abs(lch1.h - lch2.h) > Math.PI)
	{
		avg_H += Math.PI;
	}

	var delta_H = lch2.h - lch1.h;

	if(Math.abs(delta_H) > Math.PI)
	{
		if(lch2.h <= lch1.h) delta_H += Math.PI * 2;
		else delta_H -= Math.PI * 2;
	}

	delta_H = Math.sqrt(lch1.C * lch2.C) * Math.sin(delta_H) * 2;

	var T = 1
		- 0.17 * Math.cos(avg_H - Math.PI / 6)
		+ 0.24 * Math.cos(avg_H * 2)
		+ 0.32 * Math.cos(avg_H * 3 + Math.PI / 30)
		- 0.20 * Math.cos(avg_H * 4 - Math.PI * 7/20);

	var SL = avg_L - 50;
	SL *= SL;
	SL = SL * 0.015 / Math.sqrt(SL + 20) + 1;

	var SC = avg_C * 0.045 + 1;

	var SH = avg_C * T * 0.015 + 1;

	var delta_Theta = avg_H / 25 - Math.PI * 11/180;
	delta_Theta = Math.exp(delta_Theta * -delta_Theta) * (Math.PI / 6);

	var RT = Math.pow(avg_C, 7);
	RT = Math.sqrt(RT / (RT + 6103515625)) * Math.sin(delta_Theta) * -2; // 6103515625 = 25^7

	delta_L /= SL;
	delta_C /= SC;
	delta_H /= SH;

	return Math.sqrt(delta_L * delta_L + delta_C * delta_C + delta_H * delta_H + RT * delta_C * delta_H);
}

var Color =
{
	refX: 31271/32902, // normalized standard observer D65.
	refY: 1,
	refZ: 35827/32902,
	yuvmatrices:
	{
		'bt601':
		{
			name: 'ITU-R BT.601 (DVD, JPEG, Youtube)',
			rScale: 0.299,
			gScale: 0.587,
			bScale: 0.114
		},
		'bt709':
		{
			name: 'ITU-R BT.709 (HDTV)',
			rScale: 0.2125,
			gScale: 0.7154,
			bScale: 0.0721
		},
		'bt2020':
		{
			name: 'ITU-R BT.2020 (UHDTV)',
			rScale: 0.2627,
			gScale: 0.678,
			bScale: 0.0593
		},
		'smpte240m':
		{
			name: 'SMPTE 240M (very old HDTV)',
			rScale: 0.212,
			gScale: 0.701,
			bScale: 0.087
		},
		'fcc':
		{
			name: 'FCC',
			rScale: 0.3,
			gScale: 0.59,
			bScale: 0.11
		}
	},
	colorspaces:
	{
		'rgb':
		{
			name: 'RGB',
			components: ['Red', 'Green', 'Blue'],
			componentInfo:
			[
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 }
			],
			toColor: function(x) { return new ColorRGB(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.R, x.G, x.B ]; },
			conversions:
			{
				'hsl': function(x) { return x.toHSL(); },
				'hsv': function(x) { return x.toHSV(); },
				'yuv': function(x) { return x.toYUV(); },
				'yiq': function(x) { return x.toYIQ(); },
				'linear_rgb': function(x) { return x.toLinearRGB(); }
			}
		},
		'linear_rgb':
		{
			name: 'Linear RGB',
			components: ['Red', 'Green', 'Blue'],
			componentInfo:
			[
				{ minimum: 0, maximum: 1, scale: 1023 },
				{ minimum: 0, maximum: 1, scale: 1023 },
				{ minimum: 0, maximum: 1, scale: 1023 }
			],
			toColor: function(x) { return new ColorLinearRGB(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.R, x.G, x.B ]; },
			conversions:
			{
				'rgb': function(x) { return x.toRGB(); },
				'xyz': function(x) { return x.toXYZ(); },
			}
		},
		'hsl':
		{
			name: 'HSL',
			components: ['Hue', 'Saturation', 'Lightness'],
			componentInfo:
			[
				{ minimum: 0, maximum: 359, scale: 1 },
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 }
			],
			toColor: function(x) { return new ColorHSL(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.H, x.S, x.L ]; },
			conversions:
			{
				'rgb': function(x) { return x.toRGB(); }
			}
		},
		'hsv':
		{
			name: 'HSV',
			components: ['Hue', 'Saturation', 'Value'],
			componentInfo:
			[
				{ minimum: 0, maximum: 359, scale: 1 },
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 }
			],
			toColor: function(x) { return new ColorHSV(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.H, x.S, x.V ]; },
			conversions:
			{
				'rgb': function(x) { return x.toRGB(); }
			}
		},
		'yuv':
		{
			name: 'Y′UV',
			components: ['Luma', 'Chroma U', 'Chroma V'],
			componentInfo:
			[
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 }
			],
			toColor: function(x) { return new ColorYUV(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.Y, x.U, x.V ]; },
			conversions:
			{
				'rgb': function(x) { return x.toRGB(); }
			}
		},
		'yiq':
		{
			name: 'Y′IQ',
			components: ['Luma', 'Chroma I', 'Chroma Q'],
			componentInfo:
			[
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 },
				{ minimum: 0, maximum: 1, scale: 255 }
			],
			toColor: function(x) { return new ColorYIQ(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.Y, x.I, x.Q ]; },
			conversions:
			{
				'rgb': function(x) { return x.toRGB(); }
			}
		},
		'xyy':
		{
			name: 'CIE xyY',
			components: ['x', 'y', 'Y'],
			componentInfo:
			[
				{ minimum: 0, maximum: 1, scale: 100 },
				{ minimum: 0, maximum: 1, scale: 100 },
				{ minimum: 0, maximum: 1, scale: 100 }
			],
			toColor: function(x) { return new ColorxyY(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.x, x.y, x.Y ]; },
			conversions:
			{
				'xyz': function(x) { return x.toXYZ(); }
			}
		},
		'xyz':
		{
			name: 'CIE XYZ',
			components: ['X', 'Y', 'Z'],
			componentInfo:
			[
				{ minimum: 0, maximum: 0.9505, scale: 100 },
				{ minimum: 0, maximum: 1, scale: 100 },
				{ minimum: 0, maximum: 1.089, scale: 100 }
			],
			toColor: function(x) { return new ColorXYZ(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.X, x.Y, x.Z ]; },
			conversions:
			{
				'linear_rgb': function(x) { return x.toLinearRGB(); },
				'lab': function(x) { return x.toLab(); },
				'luv': function(x) { return x.toLuv(); },
				'xyy': function(x) { return x.toxyY(); }
			}
		},
		'lab':
		{
			name: 'CIE L*a*b*',
			components: ['Lightness', 'a', 'b'],
			componentInfo:
			[
				{ minimum: 0, maximum: 100, scale: 1 },
				{ minimum: -12500/29, maximum: 12500/29, scale: 1 },
				{ minimum: -5000/29, maximum: 5000/29, scale: 1 }
			],
			toColor: function(x) { return new ColorLab(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.L, x.a, x.b ]; },
			conversions:
			{
				'xyz': function(x) { return x.toXYZ(); },
				'LChab': function(x) { return x.toLChab(); }
			}
		},
		'LChab':
		{
			name: function(c)
			{
				c.appendChild(document.createTextNode('CIE L*C*h'));

				var sub = document.createElement('sub');
				sub.appendChild(document.createTextNode('ab'));
				c.appendChild(sub);
			},
			components: ['Lightness', 'Chroma', 'Hue'],
			componentInfo:
			[
				{ minimum: 0, maximum: 100, scale: 1 },
				{ minimum: 0, maximum: 4.64238345442629658e2, scale: 1 },
				{ minimum: 0, maximum: Math.PI*2, scale: 180/Math.PI }
			],
			toColor: function(x) { return new ColorLChab(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.L, x.C, x.h ]; },
			conversions:
			{
				'lab': function(x) { return x.toLab(); }
			}
		},
		'luv':
		{
			name: 'CIE L*u*v*',
			components: ['Lightness', 'u', 'v'],
			componentInfo:
			[
				{ minimum: 0, maximum: 100, scale: 1 },
				{ minimum: -81304600/316141, maximum: 720, scale: 1 },
				{ minimum: -160, maximum: 54113280/316141, scale: 1 }
			],
			toColor: function(x) { return new ColorLuv(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.L, x.u, x.v ]; },
			conversions:
			{
				'xyz': function(x) { return x.toXYZ(); },
				'LChuv': function(x) { return x.toLChuv(); }
			}
		},
		'LChuv':
		{
			name: function(c)
			{
				c.appendChild(document.createTextNode('CIE L*C*h'));

				var sub = document.createElement('sub');
				sub.appendChild(document.createTextNode('uv'));
				c.appendChild(sub);
			},
			components: ['Lightness', 'Chroma', 'Hue'],
			componentInfo:
			[
				{ minimum: 0, maximum: 100, scale: 1 },
				{ minimum: 0, maximum: 7.40066582332174237e2, scale: 1 },
				{ minimum: 0, maximum: Math.PI*2, scale: 180/Math.PI }
			],
			toColor: function(x) { return new ColorLChuv(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.L, x.C, x.h ]; },
			conversions:
			{
				'luv': function(x) { return x.toLuv(); },
				'lshuv': function(x) { return x.toLShuv(); }
			}
		},
		'lshuv':
		{
			name: function(c)
			{
				c.appendChild(document.createTextNode('CIE L*Sh'));

				var sub = document.createElement('sub');
				sub.appendChild(document.createTextNode('uv'));
				c.appendChild(sub);
			},
			components: ['Lightness', 'Saturation', 'Hue'],
			componentInfo:
			[
				{ minimum: 0, maximum: 100, scale: 1 },
				{ minimum: 0, maximum: 4.5, scale: 25 },
				{ minimum: 0, maximum: Math.PI*2, scale: 180/Math.PI }
			],
			toColor: function(x) { return new ColorLShuv(x[0], x[1], x[2]); },
			toGeneric: function(x) { return [ x.L, x.S, x.h ]; },
			conversions:
			{
				'LChuv': function(x) { return x.toLChuv(); }
			}
		}
	}
};

function updateColors(firstid, firstcolor, starting)
{
	var queue = new Array(); queue.push(firstid);

	var colors = {};
	colors[firstid] = firstcolor;

	while(queue.length > 0)
	{
		var id = queue.pop();
		var cs = Color.colorspaces[id];

		for(nextid in cs.conversions)
		{
			if(!colors[nextid])
			{
				colors[nextid] = cs.conversions[nextid](colors[id]);
				queue.push(nextid);
			}
		}
	}

	// update the text inputs.

	for(id in colors)
	{
		var cs = Color.colorspaces[id];

		var generic = cs.toGeneric(colors[id]);

		for(idx in cs.componentInfo)
		{
			var v = generic[idx] * cs.componentInfo[idx].scale;

			cs.sliders[idx].text.value = v.toFixed();

			if(starting || id != firstid)
			{
				$(cs.sliders[idx].slider).slider('option', 'value', v);
			}
		}

		$(cs.clamped).css('visibility', colors[id].clamped ? 'visible' : 'hidden');
	}

	var rgb = colors.rgb;
	$(Color.colorBar).css('background-color', 'RGB(' + (rgb.R * 100) + '%,' + (rgb.G * 100) + '%,' + (rgb.B * 100) + '%)');
}

function setupColor(table, id, cs, first)
{
	var row = table.insertRow(-1);

	if(!first)
	{
		row.className = 'color';
	}

	var col = row.insertCell(-1);
	col.rowSpan = cs.components.length;
	col.className = 'colorname';

	if(typeof(cs.name) == 'string')
	{
		col.appendChild(document.createTextNode(cs.name));
	}
	else
	{
		cs.name(col);
	}

	var sliders = {};

	cs.getColor = function(c)
	{
		if(c == undefined) c = {};

		for(idx in sliders)
		{
			if(c[idx] == undefined)
			{
				c[idx] = $(sliders[idx].slider).slider('option', 'value');
			}

			c[idx] = c[idx] / cs.componentInfo[idx].scale;
		}

		return cs.toColor(c);
	};

	function update(c)
	{
		updateColors(id, cs.getColor(c), false);
	}

	function addSlider(idx)
	{
		col = row.insertCell(-1);
		col.appendChild(document.createTextNode(cs.components[idx]));

		var div = document.createElement('div');
		div.className = 'slider';
		$(div).slider({
			value: 0,
			min: cs.componentInfo[idx].minimum * cs.componentInfo[idx].scale,
			max: cs.componentInfo[idx].maximum * cs.componentInfo[idx].scale,
			slide: function(evt, ui) { var c = {}; c[idx] = ui.value; update(c); }
		});
		col = row.insertCell(-1);
		col.appendChild(div);

		var input = document.createElement('input');
		input.type = 'text';
		input.readOnly = true;
		col = row.insertCell(-1);
		col.appendChild(input);

		sliders[idx] = { slider: div, text: input };
	}

	addSlider(0);

	if(first)
	{
		var total = 0;

		for(idx in Color.colorspaces)
		{
			total += Color.colorspaces[idx].components.length;
		}

		Color.colorBar = row.insertCell(-1);
		Color.colorBar.rowSpan = total;
		Color.colorBar.id = 'colorbar';
	}

	cs.clamped = row.insertCell(-1);
	cs.clamped.className = 'clamped';
	cs.clamped.appendChild(document.createTextNode('clamped'));
	cs.clamped.rowSpan = cs.components.length;

	for(var i = 1; i < cs.components.length; ++i)
	{
		row = table.insertRow(-1);
		addSlider(i);
	}

	cs.sliders = sliders;
}

// initialize the table.

var table = document.getElementById('colors');
var first = true;

for(cs in Color.colorspaces)
{
	setupColor(table, cs, Color.colorspaces[cs], first);
	first = false;
}

// initialize YUV coefficients select.

var yuvselect = document.getElementById('yuvmatrix');
for(id in Color.yuvmatrices)
{
	var option = document.createElement('option');
	option.value = id;
	option.selected = (id == 'bt709');

	option.appendChild(document.createTextNode(Color.yuvmatrices[id].name));
	yuvselect.appendChild(option);
}

$(yuvselect).change(function()
{
	var next = Color.yuvmatrices[yuvselect.value];

	if(!next) return;

	var rgb = Color.colorspaces['yuv'].getColor().toRGB();

	Color.yuvmatrix = next;
	updateColors('rgb', rgb, false);
});

// Delta E events.

var del1 = document.getElementById('del1');
var dea1 = document.getElementById('dea1');
var deb1 = document.getElementById('deb1');

var del2 = document.getElementById('del2');
var dea2 = document.getElementById('dea2');
var deb2 = document.getElementById('deb2');

var de1976 = document.getElementById('de1976');
var de1994ga = document.getElementById('de1994ga');
var de1994t = document.getElementById('de1994t');
var de2000 = document.getElementById('de2000');

function deChanged()
{
	var L1 = parseInt(del1.value);
	var a1 = parseInt(dea1.value);
	var b1 = parseInt(deb1.value);
	var L2 = parseInt(del2.value);
	var a2 = parseInt(dea2.value);
	var b2 = parseInt(deb2.value);

	if(L1 == NaN || a1 == NaN || b1 == NaN || L2 == NaN || a2 == NaN || b2 == NaN)
	{
		return;
	}

	var lab1 = new ColorLab(L1, a1, b1);
	var lch1 = lab1.toLChab();

	var lab2 = new ColorLab(L2, a2, b2);
	var lch2 = lab2.toLChab();

	de1976.value = deltaE1976(lab1, lab2).toFixed(2);
	de1994ga.value = deltaE1994(lab1, lab2, 'graphic arts').toFixed(2);
	de1994t.value = deltaE1994(lab1, lab2, 'textiles').toFixed(2);
	de2000.value = deltaE2000(lch1, lch2).toFixed(2);
}

var deltaeinputs = [del1,dea1,deb1,del2,dea2,deb2];

for(i in deltaeinputs)
{
	$(deltaeinputs[i]).change(deChanged);
	$(deltaeinputs[i]).keyup(deChanged);
}

// initialize data.

Color.yuvmatrix = Color.yuvmatrices['bt709'];
updateColors('rgb', new ColorRGB(0.47, 0.76, 0.91), true);

del1.value = 75;
dea1.value = -13;
deb1.value = -26;

del2.value = 70;
dea2.value = -16;
deb2.value = -28;

deChanged();

})();