The Java Developers Almanac 1.4

e663. Getting the Transparent Pixel and Number of Colors Used in a GIF Image

    // Get GIF image
    Image image = new ImageIcon("image.gif").getImage();
    
    // Get the color model; this method is implemented in
    // e662 Getting the Color Model of an Image
    IndexColorModel colorModel = (IndexColorModel)getColorModel(image);
    
    // Get transparent pixel
    int trans = colorModel.getTransparentPixel();
    if (trans == -1) {
        // There is no transparent pixel
    }
    
    // Get the number of colors
    int numColors = colorModel.getMapSize();

Related Examples

e660. Creating an Image from an Array of Color-Indexed Pixel Values
e661. Determining If an Image Has Transparent Pixels
e662. Getting the Color Model of an Image
e664. Getting a Sub-Image of an Image
e665. Filtering the RGB Values in an Image

See also: Buffered Images    Effects    Volatile Images

© 2002 Addison-Wesley.