1 /* RgbProfileConverter.java -- RGB Profile conversion class 2 Copyright (C) 2004 Free Software Foundation 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package gnu.java.awt.color; 40 41 import java.awt.color.ICC_Profile; 42 import java.awt.color.ICC_ProfileRGB; 43 import java.awt.color.ProfileDataException; 44 45 /** 46 * RgbProfileConverter - converts RGB profiles (ICC_ProfileRGB) 47 * 48 * This type of profile contains a matrix and three 49 * tone reproduction curves (TRCs). 50 * 51 * Device RGB --> CIE XYZ is done through first multiplying with 52 * a matrix, then each component is looked-up against it's TRC. 53 * 54 * The opposite transform is done using the inverse of the matrix, 55 * and TRC:s. 56 * 57 * @author Sven de Marothy 58 */ 59 public class RgbProfileConverter implements ColorSpaceConverter 60 { 61 private float[][] matrix; 62 private float[][] inv_matrix; 63 private ToneReproductionCurve rTRC; 64 private ToneReproductionCurve gTRC; 65 private ToneReproductionCurve bTRC; 66 private ColorLookUpTable toPCS; 67 private ColorLookUpTable fromPCS; 68 69 /** 70 * CIE 1931 D50 white point (in Lab coordinates) 71 */ 72 private static float[] D50 = { 0.96422f, 1.00f, 0.82521f }; 73 74 /** 75 * Constructs an RgbProfileConverter from a given ICC_ProfileRGB 76 */ RgbProfileConverter(ICC_ProfileRGB profile)77 public RgbProfileConverter(ICC_ProfileRGB profile) 78 { 79 toPCS = fromPCS = null; 80 matrix = profile.getMatrix(); 81 82 // get TRCs 83 try 84 { 85 rTRC = new ToneReproductionCurve(profile.getGamma(ICC_ProfileRGB.REDCOMPONENT)); 86 } 87 catch (ProfileDataException e) 88 { 89 rTRC = new ToneReproductionCurve(profile.getTRC(ICC_ProfileRGB.REDCOMPONENT)); 90 } 91 try 92 { 93 gTRC = new ToneReproductionCurve(profile.getGamma(ICC_ProfileRGB.GREENCOMPONENT)); 94 } 95 catch (ProfileDataException e) 96 { 97 gTRC = new ToneReproductionCurve(profile.getTRC(ICC_ProfileRGB.GREENCOMPONENT)); 98 } 99 try 100 { 101 bTRC = new ToneReproductionCurve(profile.getGamma(ICC_ProfileRGB.BLUECOMPONENT)); 102 } 103 catch (ProfileDataException e) 104 { 105 bTRC = new ToneReproductionCurve(profile.getTRC(ICC_ProfileRGB.BLUECOMPONENT)); 106 } 107 108 // If a CLUT is available, it should be used, and the TRCs ignored. 109 // Note: A valid profile may only have CLUTs in one direction, and 110 // TRC:s without useful info, making reverse-transforms impossible. 111 // In this case the TRC will be used for the reverse-transform with 112 // unpredictable results. This is in line with the Java specification, 113 try 114 { 115 toPCS = new ColorLookUpTable(profile, ICC_Profile.icSigAToB0Tag); 116 } 117 catch (Exception e) 118 { 119 toPCS = null; 120 } 121 122 try 123 { 124 fromPCS = new ColorLookUpTable(profile, ICC_Profile.icSigBToA0Tag); 125 } 126 catch (Exception e) 127 { 128 fromPCS = null; 129 } 130 131 // Calculate the inverse matrix if no reverse CLUT is available 132 if(fromPCS == null) 133 inv_matrix = invertMatrix(matrix); 134 else 135 { 136 // otherwise just set it to an identity matrix 137 inv_matrix = new float[3][3]; 138 inv_matrix[0][0] = inv_matrix[1][1] = inv_matrix[2][2] = 1.0f; 139 } 140 } 141 toCIEXYZ(float[] in)142 public float[] toCIEXYZ(float[] in) 143 { 144 // CLUT takes precedence 145 if (toPCS != null) 146 return toPCS.lookup(in); 147 148 float[] temp = new float[3]; 149 float[] out = new float[3]; 150 151 // device space --> linear gamma 152 temp[0] = rTRC.lookup(in[0]); 153 temp[1] = gTRC.lookup(in[1]); 154 temp[2] = bTRC.lookup(in[2]); 155 156 // matrix multiplication 157 out[0] = matrix[0][0] * temp[0] + matrix[0][1] * temp[1] 158 + matrix[0][2] * temp[2]; 159 out[1] = matrix[1][0] * temp[0] + matrix[1][1] * temp[1] 160 + matrix[1][2] * temp[2]; 161 out[2] = matrix[2][0] * temp[0] + matrix[2][1] * temp[1] 162 + matrix[2][2] * temp[2]; 163 164 return out; 165 } 166 toRGB(float[] in)167 public float[] toRGB(float[] in) 168 { 169 return SrgbConverter.XYZtoRGB(toCIEXYZ(in)); 170 } 171 fromCIEXYZ(float[] in)172 public float[] fromCIEXYZ(float[] in) 173 { 174 if (fromPCS != null) 175 return fromPCS.lookup(in); 176 177 float[] temp = new float[3]; 178 float[] out = new float[3]; 179 180 // matrix multiplication 181 temp[0] = inv_matrix[0][0] * in[0] + inv_matrix[0][1] * in[1] 182 + inv_matrix[0][2] * in[2]; 183 temp[1] = inv_matrix[1][0] * in[0] + inv_matrix[1][1] * in[1] 184 + inv_matrix[1][2] * in[2]; 185 temp[2] = inv_matrix[2][0] * in[0] + inv_matrix[2][1] * in[1] 186 + inv_matrix[2][2] * in[2]; 187 188 // device space --> linear gamma 189 out[0] = rTRC.reverseLookup(temp[0]); 190 out[1] = gTRC.reverseLookup(temp[1]); 191 out[2] = bTRC.reverseLookup(temp[2]); 192 193 // FIXME: Sun appears to clip the return values to [0,1] 194 // I don't believe that is a Good Thing, 195 // (some colorspaces may allow values outside that range.) 196 // So we return the actual values here. 197 return out; 198 } 199 fromRGB(float[] in)200 public float[] fromRGB(float[] in) 201 { 202 return fromCIEXYZ(SrgbConverter.RGBtoXYZ(in)); 203 } 204 205 /** 206 * Inverts a 3x3 matrix, returns the inverse, 207 * throws an IllegalArgumentException if the matrix is not 208 * invertible (this shouldn't happen for a valid profile) 209 */ invertMatrix(float[][] matrix)210 private float[][] invertMatrix(float[][] matrix) 211 { 212 float[][] out = new float[3][3]; 213 double determinant = matrix[0][0] * (matrix[1][1] * matrix[2][2] 214 - matrix[2][1] * matrix[1][2]) 215 - matrix[0][1] * (matrix[1][0] * matrix[2][2] 216 - matrix[2][0] * matrix[1][2]) 217 + matrix[0][2] * (matrix[1][0] * matrix[2][1] 218 - matrix[2][0] * matrix[1][1]); 219 220 if (determinant == 0.0) 221 throw new IllegalArgumentException("Can't invert conversion matrix."); 222 float invdet = (float) (1.0 / determinant); 223 224 out[0][0] = invdet * (matrix[1][1] * matrix[2][2] 225 - matrix[1][2] * matrix[2][1]); 226 out[0][1] = invdet * (matrix[0][2] * matrix[2][1] 227 - matrix[0][1] * matrix[2][2]); 228 out[0][2] = invdet * (matrix[0][1] * matrix[1][2] 229 - matrix[0][2] * matrix[1][1]); 230 out[1][0] = invdet * (matrix[1][2] * matrix[2][0] 231 - matrix[1][0] * matrix[2][2]); 232 out[1][1] = invdet * (matrix[0][0] * matrix[2][2] 233 - matrix[0][2] * matrix[2][0]); 234 out[1][2] = invdet * (matrix[0][2] * matrix[1][0] 235 - matrix[0][0] * matrix[1][2]); 236 out[2][0] = invdet * (matrix[1][0] * matrix[2][1] 237 - matrix[1][1] * matrix[2][0]); 238 out[2][1] = invdet * (matrix[0][1] * matrix[2][0] 239 - matrix[0][0] * matrix[2][1]); 240 out[2][2] = invdet * (matrix[0][0] * matrix[1][1] 241 - matrix[0][1] * matrix[1][0]); 242 return out; 243 } 244 } 245