Java Image Save write(Image image, ImageOutputStream ios, ImageWriter writer)

Description

write

License

Open Source License

Declaration

private static void write(Image image, ImageOutputStream ios, ImageWriter writer) throws IOException 

Method Source Code

//package com.java2s;
/*/*from  ww  w.ja  va 2 s. com*/
 * JMRTD - A Java API for accessing machine readable travel documents.
 *
 * Copyright (C) 2006 - 2012  The JMRTD team
 *
 * This library 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 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * $Id: $
 */

import java.awt.Graphics;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.PixelGrabber;
import java.awt.image.RenderedImage;

import java.io.IOException;

import java.io.OutputStream;
import java.util.Iterator;

import javax.imageio.ImageIO;

import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;

import javax.imageio.stream.ImageOutputStream;
import javax.swing.ImageIcon;

public class Main {
    /**
     * Writes an image.
     * 
     * @param image the image to write
     * @param mimeType the mime-type of the encoded image
     * @param out the output stream to write to
     * 
     * @throws IOException if the image cannot be written
     */
    public static void write(Image image, String mimeType, OutputStream out) throws IOException {
        Iterator<ImageWriter> writers = ImageIO.getImageWritersByMIMEType(mimeType);
        if (!writers.hasNext()) {
            throw new IOException("No writers for \"" + mimeType + "\"");
        }
        ImageOutputStream ios = ImageIO.createImageOutputStream(out);
        while (writers.hasNext()) {
            try {
                ImageWriter writer = (ImageWriter) writers.next();
                write(image, ios, writer);
                return;
            } catch (Exception e) {
                e.printStackTrace();
                /* NOTE: this writer doesn't work? Try next one... */
                continue;
            } finally {
                ios.flush();
            }
        }
    }

    private static void write(Image image, ImageOutputStream ios, ImageWriter writer) throws IOException {
        writer.setOutput(ios);
        ImageWriteParam pm = writer.getDefaultWriteParam();
        RenderedImage renderedImage = toBufferedImage(image);
        pm.setSourceRegion(new Rectangle(0, 0, renderedImage.getWidth(), renderedImage.getHeight()));
        writer.write(renderedImage);
    }

    /**
     * This method returns a buffered image with the contents of an image.
     * From Java Developers Almanac site.
     * TODO: Check license.
     */
    private 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();
        try {
            // 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);
        } catch (HeadlessException e) {
            // The system does not have a screen
        }

        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);
        }

        // Copy image to buffered image
        Graphics g = bimage.createGraphics();

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

        return bimage;
    }

    private 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();
    }
}

Related

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