gomp-20050608-branch/libjava/classpath/gnu/java/awt/color/GrayProfileConverter.java

   1 /* GrayProfileConverter.java -- Gray 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_ProfileGray;
  43 import java.awt.color.ProfileDataException;
  44
  45 /**
  46  * GrayProfileConverter - converts Grayscale profiles (ICC_ProfileGray)
  47  *
  48  * This type of profile contains a single tone reproduction curve (TRC).
  49  * Conversion consists of simple TRC lookup.
  50  *
  51  * This implementation is very lazy and does everything applying the TRC and
  52  * utilizing the built-in linear grayscale color space.
  53  *
  54  * @author Sven de Marothy
  55  */
  56 public class GrayProfileConverter implements ColorSpaceConverter
  57 {
  58   private GrayScaleConverter gc;
  59   private ToneReproductionCurve trc;
  60   private ColorLookUpTable toPCS;
  61   private ColorLookUpTable fromPCS;
  62
  63   /**
  64    * Constructs the converter described by an ICC_ProfileGray object
  65    */
  66   public GrayProfileConverter(ICC_ProfileGray profile)
  67   {
  68     try
  69       {
  70         trc = new ToneReproductionCurve(profile.getGamma());
  71       }
  72     catch (ProfileDataException e)
  73       {
  74         trc = new ToneReproductionCurve(profile.getTRC());
  75       }
  76
  77     // linear grayscale converter
  78     gc = new GrayScaleConverter();
  79
  80     // If a CLUT is available, it should be used, and the TRCs ignored.
  81     // Note: A valid profile may only have CLUTs in one direction, and
  82     // TRC:s without useful info, making reverse-transforms impossible.
  83     // In this case the TRC will be used for the reverse-transform with
  84     // unpredictable results. This is in line with the Java specification,
  85     try
  86       {
  87         toPCS = new ColorLookUpTable(profile, ICC_Profile.icSigAToB0Tag);
  88       }
  89     catch (Exception e)
  90       {
  91         toPCS = null;
  92       }
  93
  94     try
  95       {
  96         fromPCS = new ColorLookUpTable(profile, ICC_Profile.icSigBToA0Tag);
  97       }
  98     catch (Exception e)
  99       {
 100         fromPCS = null;
 101       }
 102   }
 103
 104   public float[] toCIEXYZ(float[] in)
 105   {
 106     if (toPCS != null)
 107       return toPCS.lookup(in);
 108     float[] gray = new float[1];
 109     gray[0] = trc.lookup(in[0]);
 110     return gc.toCIEXYZ(gray);
 111   }
 112
 113   public float[] toRGB(float[] in)
 114   {
 115     float[] gray = new float[1];
 116     gray[0] = trc.lookup(in[0]);
 117     return gc.toRGB(gray);
 118   }
 119
 120   public float[] fromRGB(float[] in)
 121   {
 122     // get linear grayscale value
 123     float[] gray = gc.fromRGB(in);
 124     gray[0] = trc.reverseLookup(gray[0]);
 125     return gray;
 126   }
 127
 128   public float[] fromCIEXYZ(float[] in)
 129   {
 130     if (fromPCS != null)
 131       return fromPCS.lookup(in);
 132
 133     float[] gray = gc.fromCIEXYZ(in);
 134     gray[0] = trc.reverseLookup(gray[0]);
 135     return gray;
 136   }
 137 }