Design of directional filters using downsampling

We present a design method of a directionally oriented 2-D filter (directional filters) and filter bank. At first, we consider the 2-D prototype passband filter. Next, using downsampling, we decimate the prototype filter coefficient and design the directional filters. The passband regions of the component filters are wedge shaped and thus provide the directional information. By using this method, we can reduce the number of filters which we must design. Finally, we show the 2-D filter bank structure with above-mentioned filter.