EFFICIENT APPROXIMATION OF GAUSSIAN FILTERS

This correspondence presents improvements to the efficient approximati on of Gaussian tilters by sequentially applying uniform hox filters. F or 1-D fitters, a simple and nearly optimal fit criterion far the leng th N of the box filters to the approximated Gaussian is given For 2-D filters, a new method is introduced to improve the circular symmetry a nd the lowpass properties of the approximation without increasing the computational complexity. Finally, a multirate implementation for larg e Gaussian filters is presented that requires significantly fewer floa ting-point operations than the standard technique.