libjava/classpath/java/awt/image/LookupOp.java

   1 /* LookupOp.java -- Filter that converts each pixel using a lookup table.
   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 java.awt.image;
  40
  41 import java.awt.Graphics2D;
  42 import java.awt.RenderingHints;
  43 import java.awt.geom.Point2D;
  44 import java.awt.geom.Rectangle2D;
  45
  46 /**
  47  * LookupOp is a filter that converts each pixel using a lookup table.
  48  *
  49  * For filtering Rasters, the lookup table must have either one component
  50  * that is applied to all bands, or one component for every band in the
  51  * Rasters.
  52  *
  53  * For BufferedImages, the lookup table may apply to both color and alpha
  54  * components.  If the lookup table contains one component, or if there are
  55  * the same number of components as color components in the source, the table
  56  * applies to all color components.  Otherwise the table applies to all
  57  * components including alpha.  Alpha premultiplication is ignored during the
  58  * lookup filtering.
  59  *
  60  * After filtering, if color conversion is necessary, the conversion happens,
  61  * taking alpha premultiplication into account.
  62  *
  63  * @author jlquinn
  64  */
  65 public class LookupOp implements BufferedImageOp, RasterOp
  66 {
  67   private LookupTable lut;
  68   private RenderingHints hints;
  69
  70   /** Construct a new LookupOp.
  71    *
  72    * @param lookup LookupTable to use.
  73    * @param hints Rendering hints (can be null).
  74    */
  75   public LookupOp(LookupTable lookup, RenderingHints hints)
  76   {
  77     lut = lookup;
  78     this.hints = hints;
  79   }
  80
  81   /* (non-Javadoc)
  82    * @see java.awt.image.BufferedImageOp#filter(java.awt.image.BufferedImage, java.awt.image.BufferedImage)
  83    */
  84   public final BufferedImage filter(BufferedImage src, BufferedImage dst)
  85   {
  86     if (src.getColorModel() instanceof IndexColorModel)
  87       throw new IllegalArgumentException("LookupOp.filter: IndexColorModel "
  88                                          + "not allowed");
  89     if (dst == null)
  90       dst = createCompatibleDestImage(src, src.getColorModel());
  91
  92     // Set up for potential colormodel mismatch
  93     BufferedImage tgt;
  94     if (dst.getColorModel().equals(src.getColorModel()))
  95       tgt = dst;
  96     else
  97       tgt = createCompatibleDestImage(src, src.getColorModel());
  98
  99     Raster sr = src.getRaster();
 100     WritableRaster dr = tgt.getRaster();
 101
 102     if (src.getColorModel().hasAlpha() &&
 103         (lut.getNumComponents() == 1 ||
 104          lut.getNumComponents() == src.getColorModel().getNumColorComponents()))
 105     {
 106       // Need to ignore alpha for lookup
 107       int[] dbuf = new int[src.getColorModel().getNumComponents()];
 108       int tmpBands = src.getColorModel().getNumColorComponents();
 109       int[] tmp = new int[tmpBands];
 110
 111       // Filter the pixels
 112       for (int y = src.getMinY(); y < src.getHeight() + src.getMinY(); y++)
 113         for (int x = src.getMinX(); x < src.getWidth() + src.getMinX(); x++)
 114         {
 115           // Filter only color components, but also copy alpha
 116           sr.getPixel(x, y, dbuf);
 117           System.arraycopy(dbuf, 0, tmp, 0, tmpBands);
 118           dr.setPixel(x, y, lut.lookupPixel(tmp, dbuf));
 119         }
 120     }
 121     else if (lut.getNumComponents() != 1
 122              &&
 123              lut.getNumComponents() != src.getColorModel().getNumComponents())
 124       throw new IllegalArgumentException("LookupOp.filter: "
 125                                          + "Incompatible lookup "
 126                                          + "table and source image");
 127
 128     // No alpha to ignore
 129     int[] dbuf = new int[src.getColorModel().getNumComponents()];
 130
 131     // Filter the pixels
 132     for (int y = src.getMinY(); y < src.getHeight() + src.getMinY(); y++)
 133       for (int x = src.getMinX(); x < src.getWidth() + src.getMinX(); x++)
 134         dr.setPixel(x, y, lut.lookupPixel(sr.getPixel(x, y, dbuf), dbuf));
 135
 136     if (tgt != dst)
 137     {
 138       // Convert between color models.
 139       // TODO Check that premultiplied alpha is handled correctly here.
 140       Graphics2D gg = dst.createGraphics();
 141       gg.setRenderingHints(hints);
 142       gg.drawImage(tgt, 0, 0, null);
 143       gg.dispose();
 144     }
 145
 146     return dst;
 147   }
 148
 149   /* (non-Javadoc)
 150    * @see java.awt.image.BufferedImageOp#getBounds2D(java.awt.image.BufferedImage)
 151    */
 152   public final Rectangle2D getBounds2D(BufferedImage src)
 153   {
 154     return src.getRaster().getBounds();
 155   }
 156
 157   /* (non-Javadoc)
 158    * @see java.awt.image.BufferedImageOp#createCompatibleDestImage(java.awt.image.BufferedImage, java.awt.image.ColorModel)
 159    */
 160   public BufferedImage createCompatibleDestImage(BufferedImage src,
 161                                                  ColorModel dstCM)
 162   {
 163     // FIXME: set properties to those in src
 164     return new BufferedImage(dstCM,
 165                              src.getRaster().createCompatibleWritableRaster(),
 166                              src.isPremultiplied, null);
 167   }
 168
 169   /** Return corresponding destination point for source point.
 170    *
 171    * LookupOp will return the value of src unchanged.
 172    * @param src The source point.
 173    * @param dst The destination point.
 174    * @see java.awt.image.RasterOp#getPoint2D(java.awt.geom.Point2D, java.awt.geom.Point2D)
 175    */
 176   public final Point2D getPoint2D(Point2D src, Point2D dst)
 177   {
 178     if (dst == null)
 179       return (Point2D) src.clone();
 180
 181     dst.setLocation(src);
 182     return dst;
 183   }
 184
 185   /** Return the LookupTable for this op. */
 186   public final LookupTable getTable()
 187   {
 188     return lut;
 189   }
 190
 191   /* (non-Javadoc)
 192    * @see java.awt.image.RasterOp#getRenderingHints()
 193    */
 194   public final RenderingHints getRenderingHints()
 195   {
 196     return hints;
 197   }
 198
 199   /** Filter a raster through a lookup table.
 200    *
 201    * Applies the lookup table for this Rasterop to each pixel of src and
 202    * puts the results in dest.  If dest is null, a new Raster is created and
 203    * returned.
 204    *
 205    * @param src The source raster.
 206    * @param dest The destination raster.
 207    * @return The WritableRaster with the filtered pixels.
 208    * @throws IllegalArgumentException if lookup table has more than one
 209    * component but not the same as src and dest.
 210    * @see java.awt.image.RasterOp#filter(java.awt.image.Raster, java.awt.image.WritableRaster)
 211    */
 212   public final WritableRaster filter(Raster src, WritableRaster dest)
 213   {
 214     if (dest == null)
 215       // Allocate a raster if needed
 216       dest = createCompatibleDestRaster(src);
 217     else
 218       if (src.getNumBands() != dest.getNumBands())
 219         throw new IllegalArgumentException();
 220
 221     if (lut.getNumComponents() != 1
 222         && lut.getNumComponents() != src.getNumBands())
 223       throw new IllegalArgumentException();
 224
 225
 226     // Allocate pixel storage.
 227     int[] tmp = new int[src.getNumBands()];
 228
 229     // Filter the pixels
 230     for (int y = src.getMinY(); y < src.getHeight() + src.getMinY(); y++)
 231       for (int x = src.getMinX(); x < src.getWidth() + src.getMinX(); x++)
 232         dest.setPixel(x, y, lut.lookupPixel(src.getPixel(x, y, tmp), tmp));
 233     return dest;
 234   }
 235
 236   /* (non-Javadoc)
 237    * @see java.awt.image.RasterOp#getBounds2D(java.awt.image.Raster)
 238    */
 239   public final Rectangle2D getBounds2D(Raster src)
 240   {
 241     return src.getBounds();
 242   }
 243
 244   /* (non-Javadoc)
 245    * @see java.awt.image.RasterOp#createCompatibleDestRaster(java.awt.image.Raster)
 246    */
 247   public WritableRaster createCompatibleDestRaster(Raster src)
 248   {
 249     return src.createCompatibleWritableRaster();
 250   }
 251
 252 }