Two design techiques for 2-D FIR LoG filters

One of the most popular technique for edge detection is based on the convolution of the image with a LoG operator namely the Laplacian of Gaussian characterized by a space constant a. We propose an approximation of this operator in the frequency domain by means of a finite impulse response filter with powers-of-two coefficients. According to the space constant value two types of realization are considered the direct form or a Chebyshev structure derived on the McClellan transformation. Both techniques lead to efficient implementation of the filters which do not require actual multipliers. Results on a test image are presented for those multiplierless filters together with those obtained by a direct computation of the LoG operator with infinite precision coefficients and it is concluded there are no significant differences.© (1990) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.