1. A method for comparing images, the method comprising: receiving a target image, wherein the target image corresponds to a target illuminated by an infrared light source during capture of the target by a camera sensitive to infrared light; receiving a color image, the color image comprising a color image of a subject; suppressing a blue component or a green component of a plurality of pixels in the color image to produce a color-suppressed image; and determining whether the target matches the subject by comparing the target image with the color-suppressed image.