LUVColorSpace

package color;import java.awt.color.ColorSpace;/** * Represents the LUV colorspace. Algorithms taken from * http://www.easyrgb.com/ *  * @author Derek Chen-Becker * */public class LUVColorSpace extends ColorSpace {	/**	 * 	 */	private static final long serialVersionUID = 1L;	public LUVColorSpace() {		super(ColorSpace.TYPE_Luv, 3);	}		// array indices	private int L = 0, U = 1, V = 2;	private int X = 0, Y = 1, Z = 2;		// Constants	private float EPSILON = 0.008856f;		private float ref_X = 96.422f;     //Observer= 2°, Illuminant= D50	private float ref_Y = 100.000f;	private float ref_Z = 82.521f;		private static ColorSpace sRGB = ColorSpace.getInstance(ColorSpace.CS_sRGB);	@Override	public float[] fromCIEXYZ(float[] colorvalue) {		float[] result = new float[3];				float var_U = ( 4 * colorvalue[X] ) / ( colorvalue[X] + ( 15 * colorvalue[Y] ) + ( 3 * colorvalue[Z] ) );		float var_V = ( 9 * colorvalue[Y] ) / ( colorvalue[X] + ( 15 * colorvalue[Y] ) + ( 3 * colorvalue[Z] ) );		float var_Y = Y / 100;		if ( var_Y > EPSILON ) {			var_Y = (float) Math.pow(var_Y, 1/3f);		} else {			var_Y = ( 7.787f * var_Y ) + ( 16f / 116f );		}		float ref_U = ( 4 * ref_X ) / ( ref_X + ( 15 * ref_Y ) + ( 3 * ref_Z ) );		float ref_V = ( 9 * ref_Y ) / ( ref_X + ( 15 * ref_Y ) + ( 3 * ref_Z ) );		result[L] = ( 116 * var_Y ) - 16;		result[U] = 13 * result[L] * ( var_U - ref_U );		result[V] = 13 * result[L] * ( var_V - ref_V );				return result;	}	@Override	public float[] fromRGB(float[] rgbvalue) {		return fromCIEXYZ(sRGB.toCIEXYZ(rgbvalue));	}	@Override	public float[] toCIEXYZ(float[] colorvalue) {		float result[] = new float[3];		float var_Y;				var_Y = ( colorvalue[L] + 16f ) / 116f;		float var_Y_cubed = (float) Math.pow(var_Y, 3); 		if ( var_Y_cubed > EPSILON ) {			var_Y = var_Y_cubed;		} else {			var_Y = ( var_Y - 16f / 116f ) / 7.787f;		}		float ref_U = ( 4 * ref_X ) / ( ref_X + ( 15 * ref_Y ) + ( 3 * ref_Z ) );		float ref_V = ( 9 * ref_Y ) / ( ref_X + ( 15 * ref_Y ) + ( 3 * ref_Z ) );		float var_U = colorvalue[U] / ( 13 * colorvalue[L] ) + ref_U;		float var_V = colorvalue[V] / ( 13 * colorvalue[L] ) + ref_V;		result[Y] = var_Y * 100;		result[X] =  - ( 9 * Y * var_U ) / ( ( var_U - 4 ) * var_V  - var_U * var_V );		result[Z] = ( 9 * Y - ( 15 * var_V * Y ) - ( var_V * X ) ) / ( 3 * var_V );				return result;	}	@Override	public float[] toRGB(float[] colorvalue) {		// convert to XYZ first, then to sRGB				return sRGB.fromCIEXYZ(toCIEXYZ(colorvalue));	}}