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copied!<p>I played recently a bit with this stuff, to display an image over another one, and to fade an image to gray.<br> Also masking an image with a mask with transparency (my previous version of this message!).</p> <p>I took my little test program and tweaked it a bit to get the wanted result.</p> <p>Here are the relevant bits:</p> <pre><code>TestMask() throws IOException { m_images = new BufferedImage[3]; m_images[0] = ImageIO.read(new File("E:/Documents/images/map.png")); m_images[1] = ImageIO.read(new File("E:/Documents/images/mapMask3.png")); Image transpImg = TransformGrayToTransparency(m_images[1]); m_images[2] = ApplyTransparency(m_images[0], transpImg); } private Image TransformGrayToTransparency(BufferedImage image) { ImageFilter filter = new RGBImageFilter() { public final int filterRGB(int x, int y, int rgb) { return (rgb << 8) & 0xFF000000; } }; ImageProducer ip = new FilteredImageSource(image.getSource(), filter); return Toolkit.getDefaultToolkit().createImage(ip); } private BufferedImage ApplyTransparency(BufferedImage image, Image mask) { BufferedImage dest = new BufferedImage( image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB); Graphics2D g2 = dest.createGraphics(); g2.drawImage(image, 0, 0, null); AlphaComposite ac = AlphaComposite.getInstance(AlphaComposite.DST_IN, 1.0F); g2.setComposite(ac); g2.drawImage(mask, 0, 0, null); g2.dispose(); return dest; } </code></pre> <p>The remainder just display the images in a little Swing panel.<br> Note that the mask image is gray levels, black becoming full transparency, white becoming full opaque.</p> <p>Although you have resolved your problem, I though I could share my take on it. It uses a slightly more Java-ish method, using standard classes to process/filter images.<br> Actually, my method uses a bit more memory (making an additional image) and I am not sure it is faster (measuring respective performances could be interesting), but it is slightly more abstract.<br> At least, you have choice! :-)</p>

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