Patent ID: 6184935
Filing Date: 2001-02-06
Classification: G06T,H04N

Abstract:
Upsampling filter circuitry for a digital video signal down conversion system which decodes a digitally encoded video signal representing a video image and decimates the decoded signal to produce a subsampled image signal that is stored for use as reference image data in decoding a subsequently received encoded image signal that is encoded as differential picture element (pixel) values relative to the earlier decoded image, the upsampling circuitry comprising:a programmable filter having a plurality of filter coefficient values;a coefficient memory which holds a plurality of filter coefficient sets, each coefficient set corresponding to a distinct subsampling phase;memory access circuitry which receives a motion vector from the encoded image signal, processes the received motion vector to locate a desired segment from the stored subsampled image signal; andcontrol circuitry which determines the subsampling phase of the desired segment from location information provided by the memory access circuitry and programs the programmable filter with the coefficient set that corresponds to the determined subsampling phase;wherein the programmable filter filters the retrieved desired segment to provide reference image data which corresponds to the decoded differential image data in image pixel position.