libjava/java/awt/image/AffineTransformOp.java

   1 /* AffineTransformOp.java --  This class performs affine
   2    transformation between two images or rasters in 2 dimensions.
   3    Copyright (C) 2004 Free Software Foundation
   4
   5 This file is part of GNU Classpath.
   6
   7 GNU Classpath is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU Classpath is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Classpath; see the file COPYING.  If not, write to the
  19 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  20 02111-1307 USA.
  21
  22 Linking this library statically or dynamically with other modules is
  23 making a combined work based on this library.  Thus, the terms and
  24 conditions of the GNU General Public License cover the whole
  25 combination.
  26
  27 As a special exception, the copyright holders of this library give you
  28 permission to link this library with independent modules to produce an
  29 executable, regardless of the license terms of these independent
  30 modules, and to copy and distribute the resulting executable under
  31 terms of your choice, provided that you also meet, for each linked
  32 independent module, the terms and conditions of the license of that
  33 module.  An independent module is a module which is not derived from
  34 or based on this library.  If you modify this library, you may extend
  35 this exception to your version of the library, but you are not
  36 obligated to do so.  If you do not wish to do so, delete this
  37 exception statement from your version. */
  38
  39 package java.awt.image;
  40
  41 import java.awt.Graphics2D;
  42 import java.awt.Rectangle;
  43 import java.awt.RenderingHints;
  44 import java.awt.geom.AffineTransform;
  45 import java.awt.geom.NoninvertibleTransformException;
  46 import java.awt.geom.Point2D;
  47 import java.awt.geom.Rectangle2D;
  48 import java.util.Arrays;
  49
  50 /**
  51  * This class performs affine transformation between two images or
  52  * rasters in 2 dimensions.
  53  *
  54  * @author Olga Rodimina (rodimina@redhat.com)
  55  */
  56 public class AffineTransformOp implements BufferedImageOp, RasterOp
  57 {
  58     public static final int TYPE_NEAREST_NEIGHBOR = 1;
  59
  60     public static final int TYPE_BILINEAR = 2;
  61
  62     /**
  63      * @since 1.5.0
  64      */
  65     public static final int TYPE_BICUBIC = 3;
  66
  67     private AffineTransform transform;
  68     private RenderingHints hints;
  69
  70     /**
  71      * Construct AffineTransformOp with the given xform and interpolationType.
  72      * Interpolation type can be TYPE_BILINEAR, TYPE_BICUBIC or
  73      * TYPE_NEAREST_NEIGHBOR.
  74      *
  75      * @param xform AffineTransform that will applied to the source image
  76      * @param interpolationType type of interpolation used
  77      */
  78     public AffineTransformOp (AffineTransform xform, int interpolationType)
  79     {
  80       this.transform = xform;
  81       if (xform.getDeterminant() == 0)
  82         throw new ImagingOpException(null);
  83
  84       switch (interpolationType)
  85       {
  86       case TYPE_BILINEAR:
  87         hints = new RenderingHints (RenderingHints.KEY_INTERPOLATION,
  88                                     RenderingHints.VALUE_INTERPOLATION_BILINEAR);
  89         break;
  90       case TYPE_BICUBIC:
  91         hints = new RenderingHints (RenderingHints.KEY_INTERPOLATION,
  92                                     RenderingHints.VALUE_INTERPOLATION_BICUBIC);
  93         break;
  94       default:
  95         hints = new RenderingHints (RenderingHints.KEY_INTERPOLATION,
  96                                     RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
  97       }
  98     }
  99
 100     /**
 101      * Construct AffineTransformOp with the given xform and rendering hints.
 102      *
 103      * @param xform AffineTransform that will applied to the source image
 104      * @param hints rendering hints that will be used during transformation
 105      */
 106     public AffineTransformOp (AffineTransform xform, RenderingHints hints)
 107     {
 108       this.transform = xform;
 109       this.hints = hints;
 110       if (xform.getDeterminant() == 0)
 111         throw new ImagingOpException(null);
 112     }
 113
 114     /**
 115      * Creates empty BufferedImage with the size equal to that of the
 116      * transformed image and correct number of bands. The newly created
 117      * image is created with the specified ColorModel.
 118      * If the ColorModel is equal to null, then image is created
 119      * with the ColorModel of the source image.
 120      *
 121      * @param src source image
 122      * @param destCM color model for the destination image
 123      * @return new compatible destination image
 124      */
 125     public BufferedImage createCompatibleDestImage (BufferedImage src,
 126                                                     ColorModel destCM)
 127     {
 128
 129       // if destCm is not specified, use color model of the source image
 130
 131       if (destCM == null)
 132         destCM = src.getColorModel ();
 133
 134       return new BufferedImage (destCM,
 135                                 createCompatibleDestRaster (src.getRaster ()),
 136                                 src.isAlphaPremultiplied (),
 137                                 null);
 138
 139     }
 140
 141     /**
 142      * Creates empty WritableRaster with the size equal to the transformed
 143      * source raster and correct number of bands
 144      *
 145      * @param src source raster
 146      * @throws RasterFormatException if resulting width or height of raster is 0
 147      * @return new compatible raster
 148      */
 149     public WritableRaster createCompatibleDestRaster (Raster src)
 150     {
 151       Rectangle rect = (Rectangle) getBounds2D (src);
 152
 153       // throw RasterFormatException if resulting width or height of the
 154       // transformed raster is 0
 155
 156       if (rect.getWidth () == 0 || rect.getHeight () == 0)
 157         throw new RasterFormatException("width or height is 0");
 158
 159       return src.createCompatibleWritableRaster ((int) rect.getWidth (),
 160                                                 (int) rect.getHeight ());
 161     }
 162
 163     /**
 164      * Transforms source image using transform specified at the constructor.
 165      * The resulting transformed image is stored in the destination image.
 166      *
 167      * @param src source image
 168      * @param dst destination image
 169      * @return transformed source image
 170      */
 171     public final BufferedImage filter (BufferedImage src, BufferedImage dst)
 172     {
 173
 174       if (dst == src)
 175         throw new IllegalArgumentException ("src image cannot be the same as the dst image");
 176
 177       // If the destination image is null, then BufferedImage is
 178       // created with ColorModel of the source image
 179
 180       if (dst == null)
 181         dst = createCompatibleDestImage(src, src.getColorModel ());
 182
 183       // FIXME: Must check if color models of src and dst images are the same.
 184       // If it is not, then source image should be converted to color model
 185       // of the destination image
 186
 187       Graphics2D gr = (Graphics2D) dst.createGraphics ();
 188       gr.setRenderingHints (hints);
 189       gr.drawImage (src, transform, null);
 190       return dst;
 191
 192     }
 193
 194     /**
 195      * Transforms source raster using transform specified at the constructor.
 196      * The resulting raster is stored in the destination raster.
 197      *
 198      * @param src source raster
 199      * @param dst destination raster
 200      * @return transformed raster
 201      */
 202     public final WritableRaster filter (Raster src, WritableRaster dst)
 203     {
 204       if (dst == src)
 205         throw new IllegalArgumentException("src image cannot be the same as"
 206                                            + " the dst image");
 207
 208       if (dst == null)
 209         dst = createCompatibleDestRaster(src);
 210
 211       if (src.getNumBands() != dst.getNumBands())
 212         throw new IllegalArgumentException("src and dst must have same number"
 213                                            + " of bands");
 214
 215       double[] dpts = new double[dst.getWidth() * 2];
 216       double[] pts = new double[dst.getWidth() * 2];
 217       for (int x = 0; x < dst.getWidth(); x++)
 218       {
 219         dpts[2 * x] = x + dst.getMinX();
 220         dpts[2 * x + 1] = x;
 221       }
 222       Rectangle srcbounds = src.getBounds();
 223       if (hints.containsValue(RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR))
 224       {
 225         for (int y = dst.getMinY(); y < dst.getMinY() + dst.getHeight(); y++)
 226           {
 227             try {
 228               transform.inverseTransform(dpts, 0, pts, 0, dst.getWidth() * 2);
 229             } catch (NoninvertibleTransformException e) {
 230               // Can't happen since the constructor traps this
 231               e.printStackTrace();
 232             }
 233
 234             for (int x = 0; x < dst.getWidth(); x++)
 235               {
 236                 if (!srcbounds.contains(pts[2 * x], pts[2 * x + 1]))
 237                   continue;
 238                 dst.setDataElements(x + dst.getMinX(), y,
 239                                     src.getDataElements((int)pts[2 * x],
 240                                                         (int)pts[2 * x + 1],
 241                                                         null));
 242               }
 243           }
 244       }
 245       else if (hints.containsValue(RenderingHints.VALUE_INTERPOLATION_BILINEAR))
 246       {
 247         double[] tmp = new double[4 * src.getNumBands()];
 248         for (int y = dst.getMinY(); y < dst.getMinY() + dst.getHeight(); y++)
 249         {
 250           try {
 251             transform.inverseTransform(dpts, 0, pts, 0, dst.getWidth() * 2);
 252           } catch (NoninvertibleTransformException e) {
 253             // Can't happen since the constructor traps this
 254             e.printStackTrace();
 255           }
 256
 257           for (int x = 0; x < dst.getWidth(); x++)
 258           {
 259             if (!srcbounds.contains(pts[2 * x], pts[2 * x + 1]))
 260               continue;
 261             int xx = (int)pts[2 * x];
 262             int yy = (int)pts[2 * x + 1];
 263             double dx = (pts[2 * x] - xx);
 264             double dy = (pts[2 * x + 1] - yy);
 265
 266             // TODO write this more intelligently
 267             if (xx == src.getMinX() + src.getWidth() - 1 ||
 268                 yy == src.getMinY() + src.getHeight() - 1)
 269             {
 270               // bottom or right edge
 271               Arrays.fill(tmp, 0);
 272               src.getPixel(xx, yy, tmp);
 273             }
 274             else
 275             {
 276               // Normal case
 277               src.getPixels(xx, yy, 2, 2, tmp);
 278               for (int b = 0; b < src.getNumBands(); b++)
 279                 tmp[b] = dx * dy * tmp[b]
 280                   + (1 - dx) * dy * tmp[b + src.getNumBands()]
 281                   + dx * (1 - dy) * tmp[b + 2 * src.getNumBands()]
 282                   + (1 - dx) * (1 - dy) * tmp[b + 3 * src.getNumBands()];
 283             }
 284             dst.setPixel(x, y, tmp);
 285           }
 286         }
 287       }
 288       else
 289       {
 290         // Bicubic
 291         throw new UnsupportedOperationException("not implemented yet");
 292       }
 293
 294       return dst;
 295     }
 296
 297     /**
 298      * Transforms source image using transform specified at the constructor and
 299      * returns bounds of the transformed image.
 300      *
 301      * @param src image to be transformed
 302      * @return bounds of the transformed image.
 303      */
 304     public final Rectangle2D getBounds2D (BufferedImage src)
 305     {
 306       return getBounds2D (src.getRaster());
 307     }
 308
 309     /**
 310      * Returns bounds of the transformed raster.
 311      *
 312      * @param src raster to be transformed
 313      * @return bounds of the transformed raster.
 314      */
 315     public final Rectangle2D getBounds2D (Raster src)
 316     {
 317       // determine new size for the transformed raster.
 318       // Need to calculate transformed coordinates of the lower right
 319       // corner of the raster. The upper left corner is always (0,0)
 320
 321       double x2 = (double) src.getWidth () + src.getMinX ();
 322       double y2 = (double) src.getHeight () + src.getMinY ();
 323       Point2D p2 = getPoint2D (new Point2D.Double (x2,y2), null);
 324
 325       Rectangle2D rect = new Rectangle (0, 0, (int) p2.getX (), (int) p2.getY ());
 326       return rect.getBounds ();
 327     }
 328
 329     /**
 330      * Returns interpolation type used during transformations
 331      *
 332      * @return interpolation type
 333      */
 334     public final int getInterpolationType ()
 335     {
 336       if(hints.containsValue (RenderingHints.VALUE_INTERPOLATION_BILINEAR))
 337         return TYPE_BILINEAR;
 338       else
 339         return TYPE_NEAREST_NEIGHBOR;
 340     }
 341
 342     /**
 343      * Returns location of the transformed source point. The resulting point
 344      * is stored in the dstPt if one is specified.
 345      *
 346      * @param srcPt point to be transformed
 347      * @param dstPt destination point
 348      * @return the location of the transformed source point.
 349      */
 350     public Point2D getPoint2D (Point2D srcPt, Point2D dstPt)
 351     {
 352       return transform.transform (srcPt, dstPt);
 353     }
 354
 355     /**
 356      * Returns rendering hints that are used during transformation.
 357      *
 358      * @return rendering hints
 359      */
 360     public final RenderingHints getRenderingHints ()
 361     {
 362       return hints;
 363     }
 364
 365     /**
 366      * Returns transform used in transformation between source and destination
 367      * image.
 368      *
 369      * @return transform
 370      */
 371     public final AffineTransform getTransform ()
 372     {
 373       return transform;
 374     }
 375 }