Subversion Repositories openrisc

/* PNGEncoder.java --

   Copyright (C) 2006 Free Software Foundation

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify

it under the terms of the GNU General Public License as published by

the Free Software Foundation; either version 2, or (at your option)

any later version.

GNU Classpath is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

General Public License for more details.

You should have received a copy of the GNU General Public License

along with GNU Classpath; see the file COPYING.  If not, write to the

Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301 USA.

Linking this library statically or dynamically with other modules is

making a combined work based on this library.  Thus, the terms and

conditions of the GNU General Public License cover the whole

combination.

As a special exception, the copyright holders of this library give you

permission to link this library with independent modules to produce an

executable, regardless of the license terms of these independent

modules, and to copy and distribute the resulting executable under

terms of your choice, provided that you also meet, for each linked

independent module, the terms and conditions of the license of that

module.  An independent module is a module which is not derived from

or based on this library.  If you modify this library, you may extend

this exception to your version of the library, but you are not

obligated to do so.  If you do not wish to do so, delete this

exception statement from your version. */

package gnu.javax.imageio.png;

import java.util.Vector;

import java.util.zip.Deflater;

import java.awt.color.ColorSpace;

import java.awt.color.ICC_ColorSpace;

import java.awt.image.BufferedImage;

import java.awt.image.ColorModel;

import java.awt.image.DataBuffer;

import java.awt.image.DataBufferByte;

import java.awt.image.DataBufferUShort;

import java.awt.image.IndexColorModel;

import java.awt.image.WritableRaster;

public class PNGEncoder

{

  /**

   * The default data chunk size. 8 kb.

   */

  private static final int defaultChunkSize = 8192;

  private PNGHeader header;

  private PNGPalette palette;

  private int stride, bpp;

  private byte[] rawData;

  private PNGICCProfile profile;

  public PNGEncoder( BufferedImage bi ) throws PNGException

  {

    ColorModel c = bi.getColorModel();

    int width = bi.getWidth();

    int height = bi.getHeight();

    int depth = 0;

    int colorType;

    boolean interlace = false;

    if( c instanceof IndexColorModel )

      {

        colorType = PNGHeader.INDEXED;

        int n = ((IndexColorModel)c).getMapSize();

        if( n <= 2 )

          depth = 1;

        else if( n <= 4 )

          depth = 2;

        else if( n <= 16 )

          depth = 4;

        else if( n <= 256 )

          depth = 8;

        else

          throw new PNGException("Depth must be <= 8 bits for indexed color.");

        palette = new PNGPalette( ((IndexColorModel)c) );

      }

    else

      {

        ColorSpace cs = c.getColorSpace();

        ColorSpace grayCS = ColorSpace.getInstance( ColorSpace.CS_GRAY );

        if( cs == grayCS || bi.getType() == BufferedImage.TYPE_BYTE_GRAY

            || bi.getType() == BufferedImage.TYPE_USHORT_GRAY )

          colorType = c.hasAlpha() ? PNGHeader.GRAYSCALE_WITH_ALPHA :

            PNGHeader.GRAYSCALE;

        else

          colorType = c.hasAlpha() ? PNGHeader.RGB_WITH_ALPHA : PNGHeader.RGB;

        // Figure out the depth

        int[] bits = c.getComponentSize();

        depth = bits[0];

        for(int i = 1; i < bits.length; i++ )

          if( bits[i] > depth ) depth = bits[i];

        if( (cs != grayCS && !cs.isCS_sRGB()) && cs instanceof ICC_ColorSpace )

          profile = new PNGICCProfile( ((ICC_ColorSpace)cs).getProfile() );

      }

    header = new PNGHeader(width, height, depth, colorType, interlace);

    stride = header.getScanlineStride(); // scanline stride

    bpp = header.bytesPerPixel(); // bytes per pixel

    getRawData( bi );

  }

  /**

   * Returns the generated header.

   */

  public PNGHeader getHeader()

  {

    return header;

  }

  /**

   * Returns the generated palette.

   */

  public PNGPalette getPalette()

  {

    return palette;

  }

  /**

   * Returns the associated ICC profile, if any.

   */

  public PNGICCProfile getProfile()

  {

    return profile;

  }

  /**

   * Encodes the raster and returns a Vector of PNGData chunks.

   */

  public Vector encodeImage()

  {

    Deflater deflater = new Deflater(); // The deflater

    boolean useFilter = PNGFilter.useFilter( header );

    byte[] lastScanline = new byte[ stride ];

    byte[] data = new byte[ rawData.length + header.getHeight() ];

    byte filterByte = PNGFilter.FILTER_NONE;

    for( int i = 0; i < header.getHeight(); i++)

      {

        byte[] scanline = new byte[ stride ];

        System.arraycopy(rawData, (i * stride), scanline, 0, stride);

        if( useFilter && i > 0)

          filterByte = PNGFilter.chooseFilter( scanline, lastScanline, bpp);

        byte[] filtered = PNGFilter.filterScanline( filterByte, scanline,

                                                    lastScanline, bpp );

        data[i * (stride + 1)] = filterByte;

        System.arraycopy(filtered, 0, data, 1 + (i * (stride + 1)), stride);

        lastScanline = scanline;

      }

    deflater.setInput( data );

    deflater.finish();

    PNGData chunk;

    Vector chunks = new Vector();

    do

      {

        chunk = new PNGData( defaultChunkSize );

        chunk.deflateToChunk( deflater );

        chunks.add( chunk );

      }

    while( chunk.chunkFull() );

    chunk.shrink(); // Shrink the last chunk.

    return chunks;

  }

  /**

   * Get the image's raw data.

   * FIXME: This may need improving on.

   */

  private void getRawData( BufferedImage bi ) throws PNGException

  {

    WritableRaster raster = bi.getRaster();

    rawData = new byte[ stride * header.getHeight() ];

    if( header.isIndexed() )

      {

        DataBuffer db = raster.getDataBuffer();

        if( !( db instanceof DataBufferByte ) )

          throw new PNGException("Unexpected DataBuffer for an IndexColorModel.");

        byte[] data = ((DataBufferByte)db).getData();

        for(int i = 0; i < header.getHeight(); i++ )

          System.arraycopy( data, i * stride, rawData, i * stride, stride );

        return;

      }

    if( header.getDepth() == 16 )

      {

        DataBuffer db = raster.getDataBuffer();

        if( !( db instanceof DataBufferUShort ) )

          throw new PNGException("Unexpected DataBuffer for 16-bit.");

        short[] data = ((DataBufferUShort)db).getData();

        for(int i = 0; i < header.getHeight(); i++ )

          for(int j = 0; j < ( stride >> 1); j++)

            {

              rawData[ j * 2 + i * stride ] = (byte)((data[j + i * (stride >> 1 )] & 0xFF00) >> 8);

              rawData[ j * 2 + i * stride + 1 ] = (byte)(data[j + i * (stride >> 1 )] & 0xFF);

            }

        return;

      }

    int size = ( header.getColorType() == PNGHeader.RGB_WITH_ALPHA ) ? 4 : 3;

    int width = header.getWidth();

    int height = header.getHeight();

    int[] pixels = bi.getRGB( 0, 0, width, height, null, 0, width );

    for( int i = 0; i < width * height; i++ )

      {

        rawData[ i * size ] = (byte)((pixels[i] & 0xFF0000) >> 16);

        rawData[ i * size + 1 ] = (byte)((pixels[i] & 0xFF00) >> 8);

        rawData[ i * size + 2 ] = (byte)(pixels[i] & 0xFF);

      }

    if( size == 4 )

      for( int i = 0; i < width * height; i++ )

        rawData[ i * size + 3 ] = (byte)((pixels[i] & 0xFF000000) >> 24);

  }

}