Directional 2D FIR Filters Synthesis Using Sigmoidal Function

This paper proposes a class of two-dimensional (2D) filters known as directional FIR filters. In the synthesis, a sigmoidal function-the complementary integral Gaussian error function is used. The 2D filters with straight and elliptical shapes are explored. A parameter modifies the selectivity of the filters. As a result, smooth magnitude responses with extremely high selectivity are obtained. Image processing examples are presented.