Memory/time optimization of 2-D filters

Two-dimensional filters are commonly used in digital image processing applications. These filters have the characteristic of processing recursive sets of instructions requiring high computational speed. In this paper, these sets are modeled as cyclic two-dimensional data flow graphs, which are also used to represent the equivalent circuit design. In this new method, such graphs are submitted to a multi-dimensional retiming in order to reduce their cycle time. Such a reduction can achieve a cycle equal to the longest atomic operation in the filter, by inserting a fixed number of registers, independent of the size of the problem, into the circuit paths. Examples, description and the correctness of our algorithm are presented in the paper.