A composite filter combining a 2-Dimension (2-D) symmetrical Mexican-hat wavelet filter and circular harmonic filter is used to perform shift- and rotational-invariant optical pattern recognition. Simulation results have shown that the method yields correlation output, in terms of correlation peak sharpness and peak-to-sidelobe ratio, the same as or better than that produced by others. The light efficiency of the proposed filters is comparable to that of a circular harmonic filter. Furthermore, even when the input pattern is of various nonuniform irradiances, the filter can recognize them.
關聯:
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS