Power-adjusted fractional power radial harmonic filters for shift- and scale-invariant pattern recognition with improved noise robustness and discrimination

A novel filter is proposed to improve the noise robustness and discriminati on capability for shift- and scale-invariant pattern recognition. The filte r is a fractional power radial harmonic filter with the power being a funct ion of the spatial frequencies. By properly selecting the power function, o ne gets a shift- and scale-invariant filter with improved noise robustness and discrimination. The flatness of the peak intensity response versus scal e change is also improved with the proposed filter. Numerical results are p resented to demonstrate the improvements. (C) 1999 Elsevier Science B.V. Al l rights reserved.