SHIFT, ROTATION AND LIMITED SCALE-INVARIANT PATTERN-RECOGNITION USINGSYNTHETIC DISCRIMINANT FUNCTIONS

Making use of the idea of synthetic discriminant functions (SDF), a si mple way to synthesize a shift, rotation and limited size correlation filter is proposed. The SDF is synthesized by superimposing four 2nd o rder circular harmonics of a training reference pattern in 4 different sizes. Computer simulation experiments have shown that the filter is indeed shift, full rotation and limited size invariant over a size ran ge from 1 to 1.82. The invariant range can be increased if more traini ng patterns are used.