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: */
045: package com.sun.media.imageioimpl.common;
046:
047: import java.awt.color.ColorSpace;
048:
049: /**
050: * Singleton class representing a simple, mathematically defined CMYK
051: * color space.
052: */
053: public 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), K1 * (1.0F - Y) };
087:
088: // Convert from linear RGB to sRGB.
089: for (int i = 0; i < 3; i++) {
090: float v = rgbvalue[i];
091:
092: if (v < 0.0F)
093: v = 0.0F;
094:
095: if (v < 0.0031308F) {
096: rgbvalue[i] = 12.92F * v;
097: } else {
098: if (v > 1.0F)
099: v = 1.0F;
100:
101: rgbvalue[i] = (float) (1.055 * Math.pow(v, power1) - 0.055);
102: }
103: }
104:
105: return rgbvalue;
106: }
107:
108: public float[] fromRGB(float[] rgbvalue) {
109: // Convert from sRGB to linear RGB.
110: for (int i = 0; i < 3; i++) {
111: if (rgbvalue[i] < 0.040449936F) {
112: rgbvalue[i] /= 12.92F;
113: } else {
114: rgbvalue[i] = (float) (Math.pow(
115: (rgbvalue[i] + 0.055) / 1.055, 2.4));
116: }
117: }
118:
119: // Convert from linear RGB to CMYK.
120: float C = 1.0F - rgbvalue[0];
121: float M = 1.0F - rgbvalue[1];
122: float Y = 1.0F - rgbvalue[2];
123: float K = Math.min(C, Math.min(M, Y));
124:
125: // If K == 1.0F, then C = M = Y = 1.0F.
126: if (K != 1.0F) {
127: float K1 = 1.0F - K;
128:
129: C = (C - K) / K1;
130: M = (M - K) / K1;
131: Y = (Y - K) / K1;
132: } else {
133: C = M = Y = 0.0F;
134: }
135:
136: return new float[] { C, M, Y, K };
137: }
138:
139: public float[] toCIEXYZ(float[] colorvalue) {
140: return csRGB.toCIEXYZ(toRGB(colorvalue));
141: }
142:
143: public float[] fromCIEXYZ(float[] xyzvalue) {
144: return fromRGB(csRGB.fromCIEXYZ(xyzvalue));
145: }
146: }
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