/**
 * Returns a new object with cropped image data. Implementations may keep a reference to the
 * original data rather than a copy. Only callable if isCropSupported() is true.
 *
 * @param left The left coordinate, 0 <= left < getWidth().
 * @param top The top coordinate, 0 <= top <= getHeight().
 * @param width The width of the rectangle to crop.
 * @param height The height of the rectangle to crop.
 * @return A cropped version of this object.
 */
public LuminanceSource crop(int left, int top, int width, int height) {
    throw new UnsupportedOperationException("This luminance source does not support cropping.");
}