Programmable horizontal line filter implemented with synchronous vector

Abstract

A synchronous vector processor (SVP) (30) is provided to realize a horizontal decimation filter by processing in input value through a plurality of parallel processing elements (40). A plurality of input pixel values (80) representing a horizontal line of information in a video display are input to a data input register (DIR) (31) of the SVP (30). Each of the processing elements (40) is associated with a filter output and is operable to perform all calculations necessary to realize a multi-tap filter structure for the associated output. This is achieved by first increasing the frequency of the input signal by inserting zeros therein and then performing a number of multiplications and additions to generate an output value for that processing element, this realizing an interpolation FIR filter algorithm. The finite impulse response (FIR) filter algorithm is defined by predetermined filter coefficients stored in a constant generator (71d). Each of the processing elements are utilized to multiply a plurality of near-neighbor input values with FIR filter coefficients that are obtained from a constant generator (71d). The resulting sum for each of the processing elements is then input to the a data output register (DOR) (16) as the filter output. The output of the SVP (30) is then input to line memory (90) that is operable to decimate the output of select ones of the processing elements of the SVP (30). This rearranges the outputs to decrease the number of output pixels for each line relative to the number of input pixels for each line.