/**
 * 
 */
package model.color;

import util.Matrix;

/**
 * Converts an RGB Image into other color spaces.
 * 
 * In particular, convert from RGB to color opponent space
 * of +R/-G, +B/-Y, BL/WH (non opponent channel)
 * @author John H. Krantz, Ph.D.
 *
 */
public class ColorComputer {
	
	private Matrix matrix = new Matrix();

	public double [][][] fromRGBtoColorOpponent(double [][][] rgbImage){
		double converted [][][] = null;
		
		converted = fromConesToColorOpp(
				        fromTriStimToCones(
				        		fromRGBtoTriStim(rgbImage)));
		
		return converted;
	}
	/**
	 * Converts and RGB image to a 1931 CIE tristimulus (XYZ)
	 * set of values
	 * @param double [][][] origImage the RGB image
	 * @return double [][][] the array of Tristimulus values
	 */
	public double [][][] fromRGBtoTriStim(double [][][] origImage){
		double triStim [][][] = null;
		triStim = new double[origImage.length][origImage[0].length][3];
		
		for (int x = 0; x < origImage.length; x ++){
			for (int y = 0; y < origImage[0].length; y ++){
				triStim[x][y] = matrix.mMult(ColorConst.RGB_TRISTIM,
						origImage[x][y]);
			}
		}
		
		return triStim;
	}
	/**
	 * Converts and image in 1931 CIE tristimulus (XYZ)
	 * set of values to cone activation values
	 * @param double [][][] origImage the trisimulus image
	 * @return double [][][] the array of cones values
	 */
	public double [][][] fromTriStimToCones(double [][][] triStim){
		double cones [][][] = null;
		cones = new double[triStim.length][triStim[0].length][3];
		
		for (int x = 0; x < triStim.length; x ++){
			for (int y = 0; y < triStim[0].length; y ++){
				cones[x][y] = matrix.mMult(ColorConst.TRISTIM_CONES,
						triStim[x][y]);
			}
		}
		
		return cones;
	}
	/**
	 * Converts and image cone activation values
	 * to color opponent channel activities
	 * @param double [][][] origImage the trisimulus image
	 * @return double [][][] the array of cones values
	 */
	public double [][][] fromConesToColorOpp(double [][][] cones){
		double colorOpp [][][] = null;
		colorOpp = new double[cones.length][cones[0].length][3];
		
		for (int x = 0; x < cones.length; x ++){
			for (int y = 0; y < cones[0].length; y ++){
				colorOpp[x][y] = matrix.mMult(ColorConst.CONES_COLOR_OPP,
						cones[x][y]);
			}
		}
		
		return colorOpp;
	}
}