Patent ID: 6975681
Filing Date: 2005-12-13
Classification: H04N

Abstract:
1. A moving picture coding method which uses intra-frame coding and forward motion compensation interframe predictive coding to a moving picture signal, in predetermined block units and at predetermined frame intervals and uses bidirectional motion compensation interframe predictive coding to plural B-frames between an I-frame and a P-frame, said I-frame being subjected to said intra-frame coding, said P-frame being subjected to said forward motion compensation interframe predictive coding, said method comprising: reducing a magnitude of a forward motion vector in accordance with a frame distance between each B-frame and a reference frame (an I- or P-frame) used for said forward motion-compensated interframe prediction, said forward motion vector being obtained in a forward motion vector search of said P-frame, and then distributing a reduced vector as a forward motion vector to each of said B-frames; performing a backward motion vector search to a B-frame following said I- or P-frame of said B-frames, with said I- or P-frame used as a reference frame; reducing a magnitude of a backward motion vector in accordance with a frame distance between each B-frame and a reference frame (an I- or P-frame) used for said backward motion vector search, said backward motion vector being obtained in said motion vector search, and then distributing a reduced vector as a backward motion vector; and using bidirectional motion compensation interframe predictive coding to each of said B-frames, based on said forward motion vector distributed and said backward motion vector distributed.