MPEG-4 shape coding with morphological enhancement

The current MPEG-4 shape coding scheme is “bitmap-based”, and consists of two steps: first, distortion is introduced by down and up scaling; then, context-based arithmetic encoding is applied. Recently bitmap-based methods have been reported to produce more irritating images than contour-based methods, while introducing a similar amount of quantization error. In this paper, we propose four morphological enhancement methods which can be used in the current MPEG-4 shape decoding process. In addition, we devise a way to let decoders know which method is the best of those four morphological operations, thus preventing post-processing processes from being “blind” about the original source images. Experimental results are given using an MPEG-4 shape codec with morphological operations