Convert an image into a buffered, compatible image

Description

Demo Code

/**/*  w ww.ja v  a  2s .com*/
 * Class to load an image from the file system
 * 
 * @author williamhooper $Id: ImageUtil.java,v 1.1 2011/02/07 07:10:25 williamhooper Exp $
 * 
 *         Copyright 2008 William Hooper
 * 
 *         This library 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 3 of the License, or (at your option) any later version.
 * 
 *         This library 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. If not, see <http://www.gnu.org/licenses/>.
 */
//package com.java2s;
import java.awt.Graphics;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.PixelGrabber;

import javax.swing.ImageIcon;

public class Main {
    /**
     * Convert an image into a buffered, compatible image
     * 
     * @param image
     * @return
     */
    public static BufferedImage toBufferedImage(Image image) {
        if (image instanceof BufferedImage) {
            return (BufferedImage) image;
        }

        /**
         * This code ensures that all the pixels in the image are loaded
         */
        image = new ImageIcon(image).getImage();

        /**
         * Determine if the image has transparent pixels; for this method's implementation, see e661 Determining If an Image Has
         * Transparent Pixels
         */
        boolean hasAlpha = hasAlpha(image);

        /**
         * Create a buffered image with a format that's compatible with the screen
         */
        BufferedImage bimage = null;
        GraphicsEnvironment ge = GraphicsEnvironment
                .getLocalGraphicsEnvironment();

        /**
         * Determine the type of transparency of the new buffered image
         */
        int transparency = Transparency.OPAQUE;
        if (hasAlpha) {
            transparency = Transparency.BITMASK;
        }

        /**
         * Create the buffered image
         */
        GraphicsDevice gs = ge.getDefaultScreenDevice();
        GraphicsConfiguration gc = gs.getDefaultConfiguration();
        bimage = gc.createCompatibleImage(image.getWidth(null),
                image.getHeight(null), transparency);

        if (bimage == null) {
            /**
             * Create a buffered image using the default color model
             */
            int type = BufferedImage.TYPE_INT_RGB;
            if (hasAlpha) {
                type = BufferedImage.TYPE_INT_ARGB;
            }
            bimage = new BufferedImage(image.getWidth(null),
                    image.getHeight(null), type);
        }

        /**
         * Get the graphics context
         */
        Graphics g = bimage.createGraphics();

        /**
         * Paint the image onto the buffered image
         */
        g.drawImage(image, 0, 0, null);
        g.dispose();

        return bimage;
    }

    /**
     * Convert an portion of an image into a buffered, compatible image
     * 
     * @param image
     * @param sx1
     * @param sy1
     * @param sx2
     * @param sy2
     * @return
     */
    public static BufferedImage toBufferedImage(Image image, int sx1,
            int sy1, int sx2, int sy2) {
        int width = (sx2 - sx1);
        int height = (sy2 - sy1);

        /**
         * This code ensures that all the pixels in the image are loaded
         */
        image = new ImageIcon(image).getImage();

        /**
         * Determine if the image has transparent pixels; for this method's implementation, see e661 Determining If an Image Has
         * Transparent Pixels
         */
        boolean hasAlpha = hasAlpha(image);

        /**
         * Create a buffered image with a format that's compatible with the screen
         */
        BufferedImage bimage = null;
        GraphicsEnvironment ge = GraphicsEnvironment
                .getLocalGraphicsEnvironment();

        /**
         * Determine the type of transparency of the new buffered image
         */
        int transparency = Transparency.OPAQUE;
        if (hasAlpha) {
            transparency = Transparency.BITMASK;
        }

        /**
         * Create the buffered image
         */
        GraphicsDevice gs = ge.getDefaultScreenDevice();
        GraphicsConfiguration gc = gs.getDefaultConfiguration();
        bimage = gc.createCompatibleImage(width, height, transparency);

        if (bimage == null) {
            /**
             * Create a buffered image using the default color model
             */
            int type = BufferedImage.TYPE_INT_RGB;
            if (hasAlpha) {
                type = BufferedImage.TYPE_INT_ARGB;
            }
            bimage = new BufferedImage(image.getWidth(null),
                    image.getHeight(null), type);
        }

        /**
         * Get the graphics context
         */
        Graphics g = bimage.createGraphics();

        /**
         * Paint the image onto the buffered image
         */
        g.drawImage(image, 0, 0, width, height, sx1, sy1, sx2, sy2, null);
        g.dispose();

        return bimage;
    }

    /**
     * Return true if the image has an alph channel
     * 
     * @param image
     * @return
     */
    public static boolean hasAlpha(Image image) {
        // If buffered image, the color model is readily available
        if (image instanceof BufferedImage) {
            BufferedImage bimage = (BufferedImage) image;
            return bimage.getColorModel().hasAlpha();
        }

        // Use a pixel grabber to retrieve the image's color model;
        // grabbing a single pixel is usually sufficient
        PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
        try {
            pg.grabPixels();
        } catch (InterruptedException e) {
        }

        // Get the image's color model
        ColorModel cm = pg.getColorModel();
        return cm.hasAlpha();
    }
}
Convert an image into a buffered, compatible image - Java 2D Graphics

Description

Demo Code

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