We consider the design of trellis codes for transmission of binary images over additive white Gaussian noise (AWGN) channels. We first model the image as a binary asymmetric Markov source (BAMS) and then design source-channel optimized (SCO) trellis codes for the BAMS and AWGN channel. The SCO codes are shown to be superior to Ungerboeck's (1982) codes by approximately 1.1 dB (64-state code, 10/sup -5/ bit error probability). Furthermore, we compare the proposed SCO system to a more traditional tandem system consisting of a Huffman code, a convolutional code, an interleaver and an Ungerboeck trellis code. Using a facsimile image, we compare the image quality of an SCO code, an Ungerboeck code, and the tandem code. The SCO code yields the best reconstructed image quality at 4-5 dB channel SNR.
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