DESIGN OF 2-DIMENSIONAL FIR DIGITAL-FILTERS BY A 2-DIMENSIONAL WLS TECHNIQUE

For two-dimensional (2-D) FIR filter design, the conventional weighted least squares (WLS) technique rearranges the filter parameters of 2-D form into their corresponding one-dimensional (1-D) form, thus result ing in expensive computation, This paper presents a new computationall y efficient WLS technique far the design of 2-D FIR filters. We introd uce a updating desired frequency response which implicitly includes th e weighting function such that the sum of weighted square errors to be minimized can be represented in a 2-D matrix form, This makes it poss ible to keep all fitter parameters in their natural 2-D form, thereby reducing the computational complexity from O(N-6) to O(N-3). It is con firmed through design. examples that the new technique is computationa lly very efficient;and leads to nearly optimal approximations. This te chnique is suitable for the design of 2-D real zero-phase FIR filters with quadrantal symmetric or antisymmetric frequency response and can also be applied to the design of 1-D FIR filters.