Multi-rate variable-quality VOP shape coder

Many MPEG-4 shape coding algorithms have been formulated to provide the user with no specific control over the rate or quality of compression. These algorithms are either optimised for high quality or low bit rate. Thus a high quality optimised algorithm will be inefficient in a low bit rate application and vice versa. Hence, to achieve a highly efficient coding algorithm, a novel multi-rate variable-quality (MRVQ) video object plane (VOP) shape coder has been developed. A MRVQ VOP shape coder is an arbitrary shape coder that uses a contour detection technique to encode the row or column where the shape contour lies. It provides a range of rates that the user can choose to suit his needs. Thus, fewer bits coding the shape of a VOP can be sent on a bandwidth limited channel while sacrificing video quality. This extends the application of this technique to a wide area of research in visual communications