Progressive image transmission with RCPT protection In this paper, a joint sourcechannel coding scheme is proposed for progressive image transmission over channels with both random bit errors and packet loss by using ratecompatible punctured Turbo codes (RCPT) protection only. Two technical components which are different from existing methods are presented. First, a data frame is divided into multiple CRC blocks before being coded by a turbo code. This is to secure a high turbo coding gain which is proportional to the data frame size. In the mean time, the beginning blocks in a frame may still be usable although the decoding of the entire frame fails. Second, instead of employing product codes, we only use RCPT, along with an interleaver, to protect images over channels with combined distortion including random errors and packet loss. With this setting, the effect of packet loss is equivalent to randomly puncturing turbo codes. As a result, the optimal allocation of channel code rates is required for the random errors only, which largely reduces the complexity of the optimization process. The effectiveness of the proposed schemes is demonstrated with extensive simulation results.

Unequal error protection using wynerziv coding for error resilience Compressed video is very sensitive to channel errors. A few bit losses can derail the entire decoding process. Thus, protecting compressed video is imperative to enable visual communications. Since different elements in a compressed video stream vary in their impact on the quality of the decoded video, unequal error protection can be used to provide efficient protection. This paper describes an unequal error protection method for protecting data elements in a video stream, via a WynerZiv encoder that consists of a coarse quantizer and a Turbo coder based lossless Slepianwolf encoder. Data elements that significantly impact the visual quality of decoded video, such as modes and motion vectors as used by H.264, are provided more parity bits than coarsely quantized transform coefficients. This results in an improvement in the quality of the decoded video when the transmitted sequence is corrupted by transmission errors, than obtained by the use of equal error protection.