code: public static BufferedImage colorizeSign(ImageGray src, BufferedImage dst, double normalize) {
  		dst = checkInputs(src, dst);
  
  		if (normalize <= 0) {
  			normalize = GImageStatistics.maxAbs(src);
  		}
  
  		if (normalize == 0) {
  			// sets the output to black
  			ConvertBufferedImage.convertTo(src,dst,true);
  			return dst;
  		}
  
  		if (src.getClass().isAssignableFrom(GrayF32.class)) {
  			return colorizeSign((GrayF32) src, dst, (float) normalize);
  		} else {
  			return colorizeSign((GrayI) src, dst, (int) normalize);
  		}
  	}
docs: <p>
  Renders a colored image where the color indicates the sign and intensity its magnitude.   The input is divided
  by normalize to render it in the appropriate scale.
  </p>
  
  @param src       Input single band image.
  @param dst       Where the image is rendered into.  If null a new BufferedImage will be created and return.
  @param normalize Used to normalize the input image. If &le; 0 then the max value will be used
  @return Rendered image.