Introduction
// This filter removes all but the red values in // an image class GetRedFilter extends RGBImageFilter { public GetRedFilter() { // When this is set to true, the filter // will work with images // whose pixels are indices into a color // table (IndexColorModel). // In such a case, the color values in // the color table are filtered. canFilterIndexColorModel = true; } // This method is called for every pixel in // the image public int filterRGB(int x, int y, int rgb) { if (x == -1) { // The pixel value is from the image's color table rather than the image itself } // Return only the red component return rgb & 0xffff0000; } }