ImageUtils.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.capedwarf.images.util;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

/**
 * @author <a href="mailto:marko.luksa@gmail.com">Marko Luksa</a>
 */
public class ImageUtils {

    public static byte[] getByteArray(RenderedImage image, String formatName) {
        try {
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            ImageIO.write(image, formatName, byteArrayOutputStream);
            return byteArrayOutputStream.toByteArray();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static BufferedImage convertToBufferedImage(byte[] byteArray) {
        try {
            return ImageIO.read(new ByteArrayInputStream(byteArray));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public static int[][] histogram(BufferedImage bufferedImage) {
        int[][] histogram = new int[3][256];
        WritableRaster raster = bufferedImage.getRaster();
        int pixel[] = new int[4];
        for (int y = 0; y < raster.getHeight(); y++) {
            for (int x = 0; x < raster.getWidth(); x++) {
                raster.getPixel(x, y, pixel);
                for (int i = 0; i < 3; i++) {
                    histogram[i][pixel[i]]++;
                }
            }
        }
        return histogram;
    }

}