Efficient Design and Implementation of 2D Zero-Phase Circular FIR Filters

This paper proposes a computationally efficient polyphase implementation of analytically designed 2D FIR filters, with circular frequency response. The design is achieved in the frequency domain and is based on 1D prototype filters with low-pass, zero-phase, maximally-flat characteristic. The 2D FIR filter transfer function results directly in factored form. The filter implementation method is described in a simpler case, namely for a smaller size of the filter kernel and of the input image. Using decimation with small factors and the block filtering approach, we obtain a very efficient filter implementation at system level, with a low computational complexity.