Cascaded anti-aliasing filter control for sampled images

Abstract

A cascaded anti-aliasing filter control circuit for sampled images has a plurality of video effects modules coupled in a chain,. each module performing a particular transform of a cascaded video effect. An input module has as inputs constants for the particular transform and a pixel address signal, and provides as outputs a new pixel address signal and a set of partial derivative signals. The new pixel address signal is input to a next module in the chain as the pixel address signal, and the set of partial derivative signals are input to a matrix multiplier. A set of partial derivative signals from the next module also are input to the matrix multiplier to produce an intermediate set of partial derivative signals. A last module has as inputs the new pixel addresses from a prior module and constants for a final one the particular transforms for the cascaded video effect, and provides as outputs a final set of partial derivative signals which are combined in an output matrix multiplier with the set of partial derivative signals from a prior matrix multiplier to produce an output set of partial derivative signals from which filter control signals are generated.