A class of 2-D recursive digital filters with separable transfer function
Ju-Hong Lee, Huann-Tarng Shieh · 1st IASTED International Symposium on Signal Processing and its Applications · 1987
A new class of 2-D recursive digital filters with separable transfer function has been introduced. Using the fact that the 2-D recursive filtering operation can be viewed as decomposable into 1-D row-wise operations, we constructed a 2-D recursive digital filter which has more general separable transfer function and thus possesses more general approximation capabilities than conventional 2-D filters. The associated stability problem is reduced to that of 1-D case. Design examples showed that the design algorithm utilizing 1-D cepstral stability test and analytic derivatives to replace numerical derivatives in performing optimization process not only guarantees stable designs, but also requires less CPU time. For filter implementation, a direct recursive implementation method based on a two-step approach was proposed. Filtering example of a digital image showed that the CPU processing time using the proposed method is less than that using conventional implementation method.