001/* ICC_ProfileRGB.java -- the ICC profile for a RGB colorspace 002 Copyright (C) 2002, 2004 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.awt.color; 040 041/** 042 * ICC_ProfileRGB - a special case of ICC_Profiles. 043 * 044 * The ICC_Profile.getInstance() method will return an instance of the 045 * ICC_ProfileRGB subclass when all the following conditions are met: 046 * The device color space of the profile is TYPE_RGB. 047 * The profile contains red, green and blue ColorantTags. 048 * The profile contains red, green and blue TRCTags. 049 * The profile contains a mediaWhitePointTag included. 050 * 051 * As per the ICC specification, the color space conversion can then 052 * be done through the following method: 053 * linearR = redTRC[deviceR] 054 * linearG = greenTRC[deviceG] 055 * linearB = blueTRC[deviceB] 056 * TRC curves are either a single gamma value, or a 1-dimensional lookup table. 057 * 058 * Followed by the matrix transform: 059 * PCS = M*linear 060 * 061 * Where PCS is the vector of profile color space (must be XYZ) coordinates, 062 * linear is the vector of linear RGB coordinates, and the matrix M is 063 * constructed from the ColorantTags, where the columns are red, green and 064 * blue respectively, and the rows are X, Y and Z. 065 * 066 * Note that if the profile contains a CLUT for the color space conversion, 067 * it should be used instead, and the TRC information ignored. 068 * 069 * @author Sven de Marothy 070 * @since 1.2 071 */ 072public class ICC_ProfileRGB extends ICC_Profile 073{ 074 /** 075 * Compatible with JDK 1.2+. 076 */ 077 private static final long serialVersionUID = 8505067385152579334L; 078 079 public static final int REDCOMPONENT = 0; 080 081 public static final int GREENCOMPONENT = 1; 082 083 public static final int BLUECOMPONENT = 2; 084 085 private transient float[][] matrix; 086 087 private transient float[] gamma; 088 089 private transient float[] whitePoint; 090 091 092 /** 093 * Package-private constructor used by ICC_ColorSpace for creating an 094 * ICC_ProfileRGB from a predefined ColorSpace (CS_LINEAR_RGB and CS_sRGB) 095 */ 096 ICC_ProfileRGB(int cspace) 097 { 098 super(cspace); 099 matrix = createMatrix(); 100 whitePoint = getXYZData(icSigMediaWhitePointTag); 101 } 102 103 /** 104 * Package-private constructor used by ICC_ColorSpace for creating an 105 * ICC_ProfileRGB from profile data. 106 */ 107 ICC_ProfileRGB(byte[] data) 108 { 109 super(data); 110 matrix = createMatrix(); 111 whitePoint = getXYZData(icSigMediaWhitePointTag); 112 } 113 114 /** 115 * Returns the media white point of the profile. 116 */ 117 public float[] getMediaWhitePoint() 118 { 119 float[] wp = new float[3]; 120 wp[0] = whitePoint[0]; 121 wp[1] = whitePoint[1]; 122 wp[2] = whitePoint[2]; 123 return wp; 124 } 125 126 /** 127 * Returns the colorant matrix of the conversion. 128 */ 129 public float[][] getMatrix() 130 { 131 float[][] mat = new float[3][3]; 132 for (int i = 0; i < 3; i++) 133 for (int j = 0; j < 3; j++) 134 mat[i][j] = matrix[i][j]; 135 return mat; 136 } 137 138 /** 139 * Returns the gamma value of a component 140 * @throws ProfileDataException if the TRC is described by a lookup 141 * table and not a gamma value. 142 */ 143 public float getGamma(int component) 144 { 145 short[] data; 146 switch (component) 147 { 148 case REDCOMPONENT: 149 data = getCurve(icSigRedTRCTag); 150 break; 151 case GREENCOMPONENT: 152 data = getCurve(icSigGreenTRCTag); 153 break; 154 case BLUECOMPONENT: 155 data = getCurve(icSigBlueTRCTag); 156 break; 157 default: 158 throw new IllegalArgumentException("Not a valid component"); 159 } 160 if (data == null) 161 throw new IllegalArgumentException("Error reading TRC"); 162 163 if (data.length != 1) 164 throw new ProfileDataException("Not a single-gamma TRC"); 165 166 // convert the unsigned 7.8 fixed-point gamma to a float. 167 float gamma = (float) (((int) data[0] & 0xFF00) >> 8); 168 double fraction = ((int) data[0] & 0x00FF) / 256.0; 169 gamma += (float) fraction; 170 return gamma; 171 } 172 173 /** 174 * Returns the TRC lookup table for a component 175 * @throws ProfileDataException if the TRC is described by a gamma 176 * value and not a lookup table. 177 */ 178 public short[] getTRC(int component) 179 { 180 short[] data; 181 switch (component) 182 { 183 case REDCOMPONENT: 184 data = getCurve(icSigRedTRCTag); 185 break; 186 case GREENCOMPONENT: 187 data = getCurve(icSigGreenTRCTag); 188 break; 189 case BLUECOMPONENT: 190 data = getCurve(icSigBlueTRCTag); 191 break; 192 default: 193 throw new IllegalArgumentException("Not a valid component"); 194 } 195 if (data == null) 196 throw new IllegalArgumentException("Error reading TRC"); 197 198 if (data.length <= 1) 199 throw new ProfileDataException("Gamma value, not a TRC table."); 200 201 return data; 202 } 203 204 /** 205 * Creates the colorspace conversion matrix from the RGB tristimulus 206 * values. 207 */ 208 private float[][] createMatrix() throws IllegalArgumentException 209 { 210 float[][] mat = new float[3][3]; 211 float[] r; 212 float[] g; 213 float[] b; 214 r = getXYZData(icSigRedColorantTag); 215 g = getXYZData(icSigGreenColorantTag); 216 b = getXYZData(icSigBlueColorantTag); 217 if (r == null || g == null || b == null) 218 throw new IllegalArgumentException("Error reading colorant tags!"); 219 for (int i = 0; i < 3; i++) 220 { 221 mat[i][0] = r[i]; 222 mat[i][1] = g[i]; 223 mat[i][2] = b[i]; 224 } 225 return mat; 226 } 227} // class ICC_ProfileRGB