High-speed systolic ladder structures for multidimensional recursive digital filters

High-speed multidimensional (MD) digital filtering is very useful for real-time video signal processing such as video image coding, bandwidth compression, sampling rate conversion and the enhancement of television signals. We propose a multilevel approach for designing high-speed systolic ladder structures for MD recursive digital filters. Based on appropriately selected 1-D filter structures for each filter dimension (or level), a large variety of MD systolic filter structures may be derived. In particular, we introduce a new 1-D filter structure that proves the most suitable structure in terms of a systolic ladder implementation, because it leads to MD ladder filter structures possessing such important properties as the shortest critical path (for filters without order augmentation), the canonic number of high-level storage registers (e.g., line and frame registers of images), and local interconnectivity.