Design of 2-D digital filters with finite wordlength coefficients

A new design technique for 2-dimensional (2-D) IIR digital filters is developed. Instead of using optimal step size in the j-th iteration of Fletcher-Powell algorithm, a suboptimal step size is used to increase the overall computation efficiency. Criteria are developed for suboptimal step size to keep the mapping matrix D_j positive definite (PD) and to ensure the stability of the transfer function. The approach does not require checking the positive definiteness of D_j or the filter stability in each iteration. A new optimization algorithm with finite wordlength coefficients is developed. The algorithm minimizes the performance error caused by truncating the filter coefficients to a specified number of bits. An example of 2-D digital filters is designed by the new method