libjava/java/awt/color/ICC_ProfileRGB.java

   1 /* ICC_ProfileRGB.java -- the ICC profile for a RGB colorspace
   2    Copyright (C) 2002, 2004 Free Software Foundation, Inc.
   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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 java.awt.color;
  40
  41 /**
  42  * ICC_ProfileRGB - a special case of ICC_Profiles.
  43  *
  44  * The ICC_Profile.getInstance() method will return an instance of the
  45  * ICC_ProfileRGB subclass when all the following conditions are met:
  46  * The device color space of the profile is TYPE_RGB.
  47  * The profile contains red, green and blue ColorantTags.
  48  * The profile contains red, green and blue TRCTags.
  49  * The profile contains a mediaWhitePointTag included.
  50  *
  51  * As per the ICC specification, the color space conversion can then
  52  * be done through the following method:
  53  * linearR = redTRC[deviceR]
  54  * linearG = greenTRC[deviceG]
  55  * linearB = blueTRC[deviceB]
  56  * TRC curves are either a single gamma value, or a 1-dimensional lookup table.
  57  *
  58  * Followed by the matrix transform:
  59  * PCS = M*linear
  60  *
  61  * Where PCS is the vector of profile color space (must be XYZ) coordinates,
  62  * linear is the vector of linear RGB coordinates, and the matrix M is
  63  * constructed from the ColorantTags, where the columns are red, green and
  64  * blue respectively, and the rows are X, Y and Z.
  65  *
  66  * Note that if the profile contains a CLUT for the color space conversion,
  67  * it should be used instead, and the TRC information ignored.
  68  *
  69  * @author Sven de Marothy
  70  * @since 1.2
  71  */
  72 public class ICC_ProfileRGB extends ICC_Profile
  73 {
  74   /**
  75    * Compatible with JDK 1.2+.
  76    */
  77   private static final long serialVersionUID = 8505067385152579334L;
  78
  79   public static final int REDCOMPONENT = 0;
  80
  81   public static final int GREENCOMPONENT = 1;
  82
  83   public static final int BLUECOMPONENT = 2;
  84
  85   private transient float[][] matrix;
  86
  87   private transient float[] gamma;
  88
  89   private transient float[] whitePoint;
  90
  91
  92   /**
  93    * Package-private constructor used by ICC_ColorSpace for creating an
  94    * ICC_ProfileRGB from a predefined ColorSpace (CS_LINEAR_RGB and CS_sRGB)
  95    */
  96   ICC_ProfileRGB(int cspace)
  97   {
  98     super(cspace);
  99     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