SHIFT-AND-SCALE-INVARIANT PATTERN-RECOGNITION USING AN ELLIPTIC COORDINATE-TRANSFORMED PHASE-ONLY FILTER

A shift-and-scale-invariant elliptic coordinate-transformed phase-only filter in proposed. The filter is built in three steps: the complex conjugate of a basic-size target spectrum is calculated, its phase-only part is taken, and then the elliptic coordinate transformation is made. In the extreme case the scale ratio of recognizable objects equals 1:1.5, permitting good recognition of object sizes S within the range 0.83 less-than-or-equal-to S less-than-or-equal-to 1.25. Discrimination abilities and relative Horner efficiencies of a few versions of the filter are calculated.