Source for gnu.javax.imageio.bmp.DecodeRGB24

   1: /* DecodeRGB24.java --
   2:    Copyright (C)  2005  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., 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: package gnu.javax.imageio.bmp;
  39: 
  40: import java.io.IOException;
  41: import javax.imageio.stream.ImageInputStream;
  42: import java.awt.image.BufferedImage;
  43: import java.awt.Dimension;
  44: 
  45: public class DecodeRGB24 extends BMPDecoder {
  46: 
  47:     public DecodeRGB24(BMPFileHeader fh, BMPInfoHeader ih){
  48:         super(fh, ih);
  49:     }
  50: 
  51:     public BufferedImage decode(ImageInputStream in) throws IOException, BMPException {
  52:         skipToImage(in);
  53: 
  54:         Dimension d = infoHeader.getSize();
  55:         int h = (int)d.getHeight();
  56:         int w = (int)d.getWidth();
  57:         BufferedImage image = new BufferedImage(w, h,
  58:                                                 BufferedImage.TYPE_INT_RGB);
  59:         // BMP scanlines are padded to dword offsets
  60:         int scansize = ((w*3 & 3) != 0)? w*3 + 4 - (w*3 & 3): w*3;
  61:         int[] data = new int[w*h];
  62: 
  63:         for(int y=h-1;y>=0;y--){
  64:             byte[] scanline = new byte[scansize];
  65:             if(in.read(scanline) != scansize)
  66:                 throw new IOException("Couldn't read image data.");
  67: 
  68:             for(int x=0;x<w;x++)
  69:                 data[x + y*w] = scanline[x*3] +
  70:                     (scanline[x*3+1] << 8) +
  71:                     (scanline[x*3+2] << 16);
  72:         }
  73:         image.setRGB(0, 0, w, h, data, 0, w);
  74:         return image;
  75:     }
  76: 
  77: }