On constructing the Huffman-code-based reversible variable-length codes

In this letter, we propose a generic and efficient algorithm that can const ruct both asymmetrical and symmetrical reversible variable-length codes (RV LCs). Starting from a given Huffman code, the construction is based on two developed code-word selection mechanisms, for the symmetrical case and the asymmetrical case, respectively, it is shown that the two mechanisms posses s simple features and can generate efficient RVLCs easily. In addition, two new asymmetrical RVLCs are constructe and shown to be very efficient for f urther reducing the coding overheads in MPEG-4 when operating in the revers ible decoding mode.