Choong Seng Boon

Template-based video coding with opacity representation

We describe an image coding scheme based on multiple templates for interactive audio-visual (AN) database retrieval. The image sequence to be coded consists of overlapping image planes with opacity information and depth ordering. In this method, each image plane is independently encoded to a different bit stream where each video object sequence is reconstructed from representative frames (i.e., templates) by global and local deformations. Owing to this coding scheme, the following new functionalities are supported: identification and manipulation of two-dimensional (2-D) video objects, selective decoding and browsing of visual contents, and very high compression efficiency. We have extended an MPEG1 coding software to an object-based coding software. Experimental results of the proposed scheme prove the above advantages.

Motion compensation method for moving pictures with binary shape

This paper describes a motion compensation method for arbitrarily shaped moving visual objects. To utilise both the inter-frame correlation and the texture-shape correlation, we use macroblock-based motion compensation for binary shape coding as well as texture coding. To efficiently achieve motion compensation for a moving binary shape, we introduce extra motion vectors for the shape coding in addition to the texture motion vectors, where the shape motion vectors are coded by referring to the texture motion vectors. The proposed method can successfully save more than 50% of the number of bits in comparison with the intra-only method. The effectiveness of the proposed method has been established through MPEG4 standardisation activity, and the proposed motion-compensation framework has been adopted by the MPEG-4 visual coding standard (ISO 14496-2).