S. Perreault, H. H. Arsenault, A. Bergeron "Nonlinear pattern recognition for the quality control of chips on circuit boards" Proc. of SPIE, 5227:36-43, 2003
Abstract: Quality control of integrated circuits using pattern recognition is usually carried out in a controlled environment. Colored pigments on the serial numbers of chips cause variations of intensity of the reflected light. So there is a need for methods to detect targets independently of the illumination. We apply a technique that yields correlation peaks that are invariant under a linear transformation of object intensity, for the detection of chips on integrated circuits. The method can identify the chip, detect if the chips are present or absent, if it is the wrong chip and if it is placed and oriented correctly.
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