A Time-Recursive Interpolation Filter for Motion Compensated Prediction Considering Aliasing

COMPENSATED PREDICTION CONSIDERING ALIASING Thomas Wedi Institut fuer Theoretische Nachrichtentechnik und Informationsverarbeitung Universitaet Hannover, Appelstr. 9A, 30167 Hannover, Germany Email: [email protected] ABSTRACT In this paper a new interpolation lter for motion compensated prediction in a hybrid video codec is presented. It allows to interpolate an aliasing a ected image signal more accurate than conventional interpolation lters like bilinear or Wiener lter. In contrast to conventional lters, the new time-recursive lter uses not only the image signal of the current frame, but also the image signal of previous frames in order to interpolate the current frame. The lter has been tested with synthetic and real sequences. The experimental results for the synthetic sequence show, that with conventional lters it is not possible to predict an aliasing a ected image perfectly, even if the estimated displacements perfectly t to the sequence. Furthermore it is shown, that with the new lter it is possible to predict an aliasing a ected image perfectly. For the used real sequence a coding gain of 0.8 dB is achieved compared to an MPEG-4 codec.