An image display method comprises: color coding a second image respective to an intensity spectrum with a portion or portions of the intensity spectrum set to be transparent to generate a color coded second image; combining a first image and the color coded second image to generate a fused image; and displaying the fused image. An image display system comprises: an image generating module configured to generate an image by color coding an input image in accordance with a colormap assigning colors to intensities of an intensity spectrum; a colormap modifying module configured to select a portion of the intensity spectrum to be transparent; and a display configured to display the generated image.