SELECTIVE CODING SCHEME FOR RECONSTRUCTING AN INTEREST REGION WITH HIGH-QUALITY

In the circumstances we want to deal with, trans mission channel is li mited and global motion can happen by camera movement, and also there exists a region-of-interest (ROI) which is more important than backgro und. So very low bit rate coding algorithm is required and processing of global motion must be considered. Also ROI must be reconstructed wi th required quality after decoding because of its importance. But the existing methods such as H.261, H.263 are not suitable for such situat ions because they do not compensate global motion, which needs large a mount of transmission bits in motion information and degrades image qu ality. And also they can not reconstruct ROI's with high qualify becau se they do not consider the fact that ROI's are more important than ba ckground. So a new coding scheme is proposed that describes a method f or encoding image sequences distinguishing bits between ROI and backgr ound. Simulations show that the suggested algorithm performs well espe cially in the circumstances where background changes and the area of R OI is small enough compared with that of background.