Reversible variable length codes for efficient and robust image and video coding

Abstract

The International Telecommunications Union (ITU) has adopted reversible variable length codes (RVLCs) for use in the emerging H.263+ video compression standard. As the name suggests, these codes can be decoded in two directions and can therefore be used by a decoder to enhance robustness in the presence of transmission bit errors. In addition, these RVLCs involve little or no efficiency loss relative to the corresponding non-reversible variable length codes. We present the ideas behind two general classes of RVLCs and discuss the results of applying these codes in the framework of the H.263+ and MPEG-4 video coding standards.