001/*
002 * $RCSfile: SimpleCMYKColorSpace.java,v $
003 *
004 * 
005 * Copyright (c) 2005 Sun Microsystems, Inc. All  Rights Reserved.
006 * 
007 * Redistribution and use in source and binary forms, with or without
008 * modification, are permitted provided that the following conditions
009 * are met: 
010 * 
011 * - Redistribution of source code must retain the above copyright 
012 *   notice, this  list of conditions and the following disclaimer.
013 * 
014 * - Redistribution in binary form must reproduce the above copyright
015 *   notice, this list of conditions and the following disclaimer in 
016 *   the documentation and/or other materials provided with the
017 *   distribution.
018 * 
019 * Neither the name of Sun Microsystems, Inc. or the names of 
020 * contributors may be used to endorse or promote products derived 
021 * from this software without specific prior written permission.
022 * 
023 * This software is provided "AS IS," without a warranty of any 
024 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
025 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
026 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
027 * EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL 
028 * NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF 
029 * USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
030 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR 
031 * ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL,
032 * CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND
033 * REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF OR
034 * INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
035 * POSSIBILITY OF SUCH DAMAGES. 
036 * 
037 * You acknowledge that this software is not designed or intended for 
038 * use in the design, construction, operation or maintenance of any 
039 * nuclear facility. 
040 *
041 * $Revision: 1.5 $
042 * $Date: 2006/02/17 19:08:24 $
043 * $State: Exp $
044 */
045package com.github.jaiimageio.impl.common;
046
047import java.awt.color.ColorSpace;
048
049/**
050 * Singleton class representing a simple, mathematically defined CMYK
051 * color space.
052 */
053public final class SimpleCMYKColorSpace extends ColorSpace {
054    private static ColorSpace theInstance = null;
055    private ColorSpace csRGB;
056
057    /** The exponent for gamma correction. */
058    private static final double power1 = 1.0 / 2.4;
059
060    public static final synchronized ColorSpace getInstance() {
061        if(theInstance == null) {
062            theInstance = new SimpleCMYKColorSpace();
063        }
064        return theInstance;
065    }
066
067    private SimpleCMYKColorSpace() {
068        super(TYPE_CMYK, 4);
069        csRGB = ColorSpace.getInstance(ColorSpace.CS_LINEAR_RGB);
070    }
071
072    public boolean equals(Object o) {
073        return o != null && o instanceof SimpleCMYKColorSpace;
074    }
075
076    public float[] toRGB(float[] colorvalue) {
077        float C = colorvalue[0];
078        float M = colorvalue[1];
079        float Y = colorvalue[2];
080        float K = colorvalue[3];
081
082        float K1 = 1.0F - K;
083
084        // Convert from CMYK to linear RGB.
085        float[] rgbvalue = new float[] {K1*(1.0F - C),
086                                        K1*(1.0F - M),
087                                        K1*(1.0F - Y)};
088
089        // Convert from linear RGB to sRGB.
090        for (int i = 0; i < 3; i++) {
091            float v = rgbvalue[i];
092
093            if (v < 0.0F) v = 0.0F;
094
095            if (v < 0.0031308F) {
096                rgbvalue[i] = 12.92F * v;
097            } else {
098                if (v > 1.0F) v = 1.0F;
099
100                rgbvalue[i] = (float)(1.055 * Math.pow(v, power1) - 0.055);
101            }
102        }
103
104        return rgbvalue;
105    }
106
107    public float[] fromRGB(float[] rgbvalue) {
108        // Convert from sRGB to linear RGB.
109        for (int i = 0; i < 3; i++) {
110            if (rgbvalue[i] < 0.040449936F) {
111                rgbvalue[i] /= 12.92F;
112            } else {
113                rgbvalue[i] =
114                (float)(Math.pow((rgbvalue[i] + 0.055)/1.055, 2.4));
115            }
116        }
117
118        // Convert from linear RGB to CMYK.
119        float C = 1.0F - rgbvalue[0];
120        float M = 1.0F - rgbvalue[1];
121        float Y = 1.0F - rgbvalue[2];
122        float K = Math.min(C, Math.min(M, Y));
123
124        // If K == 1.0F, then C = M = Y = 1.0F.
125        if(K != 1.0F) {
126            float K1 = 1.0F - K;
127
128            C = (C - K)/K1;
129            M = (M - K)/K1;
130            Y = (Y - K)/K1;
131        } else {
132            C = M = Y = 0.0F;
133        }
134
135        return new float[] {C, M, Y, K};
136    }
137
138    public float[] toCIEXYZ(float[] colorvalue) {
139        return csRGB.toCIEXYZ(toRGB(colorvalue));
140    }
141
142    public float[] fromCIEXYZ(float[] xyzvalue) {
143        return fromRGB(csRGB.fromCIEXYZ(xyzvalue));
144    }
145}