An approach to region coding for content-based scalable video

We propose a scheme for coding sub-regions in video scenes to provide content-based scalable video. For each region, a special color is used to represent the non-object area, and the resulting frames are coded using conventional video coding algorithms. At the decoder, the region shape is recovered based on chroma keying, and hence content-based manipulations are made possible. A number of techniques that eliminate boundary artifacts common to region-based coding are presented. In this scheme, no explicit shape coding is needed, and the advantages of existing coding algorithms are retained. This scheme was submitted to ISO MPEG-4, and performed very well in the subjective tests.