THE ERPC - AN EFFICIENT ERROR-RESILIENT TECHNIQUE FOR ENCODING POSITIONAL INFORMATION OR SPARSE DATA

In many source and data compression schemes, information relating to positions of high-energy samples or areas of importance often needs to be relayed to the decoder. The error resilient positional code (ERPC) is an efficient fixed rate coding scheme for encoding such positional information, or equivalently, sparse binary data patterns. It has also been designed with good channel error robustness properties, such that the decoded data quality degrades gracefully with worsening channel conditions, without the possibility of catastrophic breakdown or loss of sync. In this paper, the coding efficiency of the ERPC is compared to a few other standard schemes, and as well as being efficient, its error extension in terms of the expected number of samples corrupted per bit error, is reported and shown to be low and noncatastrophic. The ERPC is applied to an image coding example based on subband coding and vector quantization. It results in an efficient adaptive codec capable of operating in harsh channel conditions, without the aid of error correction or detection techniques.