The present invention relates to a system for imaging the surface of a
substrate through a coating on the substrate. The system includes an
infrared light source positioned to cast an infrared light upon the
substrate to thereby create reflected light. A focal plane array may be
positioned to receive the reflected light and generate an image
therefrom. At least one optical filter may be disposed between the
substrate and the focal plane array so as to pass only coating
transparent wavelengths of the reflected light along an optical path
between the infrared light source and the focal plane array thereby
visually revealing irregular structural features of the substrate as at
least one image.