Image coding with robust channel-optimized trellis-coded quantization

This paper presents a wavelet-based image coder that is optimized for trans mission over the binary symmetric channel (BSC), The proposed coder uses a robust channel-optimized trellis-coded quantization (COTCQ) stage that is d esigned to optimize the image coding based on the channel characteristics. A phase scrambling stage is also used to further increase the coding perfor mance and robustness to nonstationary signals and channels. The resilience to channel errors is obtained by optimizing the coder performance only at t he level of the source encoder with no explicit channel coding for error pr otection, For the considered TCQ trellis structure, a general expression is derived for the transition probability matrix in terms of the TCQ encoding rate and tbe channel bit error rate, and is used to design the COTCQ stage of the image coder The robust nature of the coder also increases the secur ity level of the encoded bit stream and provides a much more visually pleas ing rendition of the decoded image. Examples are presented to illustrate th e performance of the proposed robust image coder.