Hybrid global-local motion compensated frame interpolation for low bit rate video coding

Abstract

A hybrid global-local motion compensated frame interpolation (HMCI) scheme for low bit rate video coding is proposed in this paper. Different from most other global-local motion compensation algorithms, which were performed at the encoder end, the proposed scheme works solely on the decoded video stream. Thus, it can be applied to any MCP (motion compensated prediction) based standard coders without bit stream syntax modification. Along with the proposed HMCI scheme, a motion-based foreground-background segmentation method is presented. Traditional intensity-based segmentation methods can only segment moving objects from still background. In contrast, the proposed approach can segment foreground objects from both moving and still background by exploiting information carried by block-based motion vectors. Both the six-parameter affine or the eight-parameter perspective models can be applied to the foreground-background segmentation and the moving background reconstruction; while the six-parameter affine model with triangular patch warping is adopted to reconstruct the foreground blocks due to its low complexity. Experiments show that the proposed HMCI scheme achieves higher subjective (visual) quality compared to the conventional block-based frame interpolation without global motion compensation, where artifacts in moving backgrounds are significantly reduced. (C) 2003 Elsevier Science (USA). All rights reserved.