ImageUtilities.java Source code

Introduction

Here is the source code for ImageUtilities.java

Source

/*
 * JSwiff is an open source Java API for Macromedia Flash file generation
 * and manipulation
 *
 * Copyright (C) 2004-2006 Ralf Terdic (contact@jswiff.com)
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

//package com.jswiff.util;

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Locale;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
import javax.imageio.stream.ImageInputStream;
import javax.imageio.stream.ImageOutputStream;

/**
 * Provides utility methods for image processing.
 * 
 * @author <a href="mailto:ralf@terdic.de">Ralf Terdic</a>
 */
public class ImageUtilities {
    /**
     * Returns the format of an image (as string).
     * 
     * @param stream
     *            image source stream
     * 
     * @return format stream (e.g. "JPEG")
     * 
     * @throws IOException
     *             if an I/O error occured
     */
    public static String getFormat(InputStream stream) throws IOException {
        ImageInputStream iis = ImageIO.createImageInputStream(stream);
        Iterator iter = ImageIO.getImageReaders(iis);
        if (!iter.hasNext()) {
            throw new IOException("Unsupported image format!");
        }
        ImageReader reader = (ImageReader) iter.next();
        iis.close();
        return reader.getFormatName();
    }

    /**
     * Loads an image from a stream.
     * 
     * @param stream
     *            input stream
     * 
     * @return the loaded image
     * 
     * @throws IOException
     *             if the image could not be loaded
     */
    public static BufferedImage loadImage(InputStream stream) throws IOException {
        return ImageIO.read(stream);
    }

    /**
     * Writes an image to an output stream as a JPEG file.
     * 
     * @param image
     *            image to be written
     * @param stream
     *            target stream
     * 
     * @throws IOException
     *             if an I/O error occured
     */
    public static void saveImageAsJPEG(BufferedImage image, OutputStream stream) throws IOException {
        ImageIO.write(image, "jpg", stream);
    }

    /**
     * Writes an image to an output stream as a JPEG file. The JPEG quality can
     * be specified in percent.
     * 
     * @param image
     *            image to be written
     * @param stream
     *            target stream
     * @param qualityPercent
     *            JPEG quality in percent
     * 
     * @throws IOException
     *             if an I/O error occured
     * @throws IllegalArgumentException
     *             if qualityPercent not between 0 and 100
     */
    public static void saveImageAsJPEG(BufferedImage image, OutputStream stream, int qualityPercent)
            throws IOException {
        if ((qualityPercent < 0) || (qualityPercent > 100)) {
            throw new IllegalArgumentException("Quality out of bounds!");
        }
        float quality = qualityPercent / 100f;
        ImageWriter writer = null;
        Iterator iter = ImageIO.getImageWritersByFormatName("jpg");
        if (iter.hasNext()) {
            writer = (ImageWriter) iter.next();
        }
        ImageOutputStream ios = ImageIO.createImageOutputStream(stream);
        writer.setOutput(ios);
        ImageWriteParam iwparam = new JPEGImageWriteParam(Locale.getDefault());
        iwparam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
        iwparam.setCompressionQuality(quality);
        writer.write(null, new IIOImage(image, null, null), iwparam);
        ios.flush();
        writer.dispose();
        ios.close();
    }

    /**
     * Writes an image to an output stream as a PNG file.
     * 
     * @param image
     *            image to be written
     * @param stream
     *            target stream
     * 
     * @throws IOException
     *             if an I/O error occured
     */
    public static void saveImageAsPNG(BufferedImage image, OutputStream stream) throws IOException {
        ImageIO.write(image, "png", stream);
    }

    private static BufferedImage convertToARGB(BufferedImage srcImage) {
        BufferedImage newImage = new BufferedImage(srcImage.getWidth(null), srcImage.getHeight(null),
                BufferedImage.TYPE_INT_ARGB);
        Graphics bg = newImage.getGraphics();
        bg.drawImage(srcImage, 0, 0, null);
        bg.dispose();
        return newImage;
    }
}