osmb.program.tiledatawriter.TileImageJpegDataWriter.java Source code

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Here is the source code for osmb.program.tiledatawriter.TileImageJpegDataWriter.java

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/*******************************************************************************
 * Copyright (c) OSMCB developers
 * 
 * This program 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 of the License, or
 * (at your option) any later version.
 * 
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package osmb.program.tiledatawriter;

import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.ImageOutputStream;

import org.apache.commons.io.output.NullOutputStream;
import org.apache.log4j.Logger;

import osmb.program.tiles.TileImageType;

public class TileImageJpegDataWriter implements IfTileImageDataWriter {
    protected static final Logger log = Logger.getLogger(TileImageJpegDataWriter.class);

    protected ImageWriter jpegImageWriter = null;

    protected ImageWriteParam iwp = null;

    protected float jpegCompressionLevel;

    /**
     * 
     * @param jpegCompressionLevel
     *          a float between 0 and 1; 1 specifies minimum compression and maximum quality
     */
    public TileImageJpegDataWriter(double jpegCompressionLevel) {
        this((float) jpegCompressionLevel);
    }

    public TileImageJpegDataWriter(float jpegCompressionLevel) {
        this.jpegCompressionLevel = jpegCompressionLevel;
    }

    public TileImageJpegDataWriter(TileImageJpegDataWriter jpegWriter) {
        this(jpegWriter.getJpegCompressionLevel());
    }

    @Override
    public void initialize() {
        if (log.isTraceEnabled()) {
            String s = "Available JPEG image writers:";
            Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpeg");
            while (writers.hasNext()) {
                ImageWriter w = writers.next();
                s += "\n\t" + w.getClass().getName();
            }
            log.trace(s);
        }
        jpegImageWriter = ImageIO.getImageWritersByFormatName("jpeg").next();
        if (jpegImageWriter == null)
            throw new NullPointerException("Unable to create a JPEG image writer");
        jpegImageWriter.addIIOWriteWarningListener(ImageWriterWarningListener.INSTANCE);
        log.debug("Used JPEG image writer: " + jpegImageWriter.getClass().getName());
        iwp = jpegImageWriter.getDefaultWriteParam();
        iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
        iwp.setCompressionQuality(jpegCompressionLevel);
    }

    public void setJpegCompressionLevel(float jpegCompressionLevel) {
        this.jpegCompressionLevel = jpegCompressionLevel;
        iwp.setCompressionQuality(jpegCompressionLevel);
    }

    public float getJpegCompressionLevel() {
        return jpegCompressionLevel;
    }

    @Override
    public void processImage(BufferedImage image, OutputStream out) throws IOException {
        if (image.getColorModel().hasAlpha()) {
            // Javas JPEG writes has a bug when the image has alpha transparency
            // see http://stackoverflow.com/questions/4386446/problem-using-imageio-write-jpg-file

            BufferedImage imageRGB = new BufferedImage(image.getWidth(), image.getHeight(),
                    BufferedImage.TYPE_INT_RGB);
            Graphics2D g = imageRGB.createGraphics();
            g.drawImage(image, null, 0, 0);
            g.dispose();
            image = imageRGB;
        }

        ImageOutputStream imageOut = ImageIO.createImageOutputStream(out);
        jpegImageWriter.setOutput(imageOut);
        IIOImage ioImage = new IIOImage(image, null, null);
        jpegImageWriter.write(null, ioImage, iwp);
    }

    @Override
    public void dispose() {
        jpegImageWriter.dispose();
        jpegImageWriter = null;
    }

    @Override
    public TileImageType getType() {
        return TileImageType.JPG;
    }

    public static boolean performOpenJDKJpegTest() {
        try {
            TileImageJpegDataWriter writer = new TileImageJpegDataWriter(0.99d);
            writer.initialize();
            OutputStream out = new NullOutputStream();
            BufferedImage image = new BufferedImage(10, 10, BufferedImage.TYPE_INT_ARGB);
            writer.processImage(image, out);
            return true;
        } catch (Exception e) {
            log.debug("Jpeg test failed", e);
            return false;
        }
    }
}