Mega Code Archive
Image Utils
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/**
* Balloontip - Balloon tips for Java Swing applications
* Copyright 2007, 2008 Bernhard Pauler, Tim Molderez
*
* This file is part of Balloontip.
*
* Balloontip 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 3 of the License, or
* (at your option) any later version.
*
* Balloontip 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 Balloontip. If not, see <http://www.gnu.org/licenses/>.
*/
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.Transparency;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.PixelGrabber;
import javax.swing.ImageIcon;
/**
* Some methods for use with an Image
* @author Tim Molderez
*/
public class ImageUtils {
/*
* Disallow instantiating this class
*/
private ImageUtils() {};
/**
* This method returns true if the specified image has transparent pixels
* This snippet was taken from: http://www.exampledepot.com/egs/java.awt.image/HasAlpha.html
* @param image
* @return True if the image has any transparency
*/
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();
}
/**
* This method returns a buffered image with the contents of an image
* This snippet was taken from: http://www.exampledepot.com/egs/java.awt.image/Image2Buf.html
* @param image
* @return The buffered image
*/
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();
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;
}
}
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