Abstract: A system and method for detecting defects on a painted workpiece surface. The system includes an elongated line of light having a pair of sharp transition zones. The line of light falls onto a moving substrate containing a plurality of workpieces to be inspected. An area detector receives light scattered by the workpiece surface. A first image is captured proximate one edge of the line of light and a second image is captured proximate the other. A defect on the workpiece produces characteristic shadow or backscatter patterns which vary between the first and second images. The shadow and backscatter patterns cause variations in the amplitude of light detected by the detector. The image data is then digitized and electronically processed by software which recognizes each defect, and characterizes the defect by type and/or size.

Abstract: A method and system are provided for inspecting a low gloss surface (12) of an object (14) at a vision station utilizing a regular, extended pattern of infrared radiation. The system includes an infrared radiation source (10) and an infrared image converter and/or infrared cameras (16) to automatically locate a surface defect in the object. A signal processor processes a first set of electrical signals from the infrared cameras to obtain a second set of electrical signals which represent pattern distortions in the reflected infrared radiation signal caused by the surface defect in order to locate the surface defect in the object. The second set of electrical signals may be processed to classify the surface defect in the object as being an “in-dent” or an “out-dent”.