Fixed-Error Encoding For Bandwidth Compression

We present a DPCM technique that uses a fixed-error approach to minimize the loss of information in compression of a picture. The technique uses an initial N-bit quantization of the image and zero-error encoding of the difference signal. It produces no slope overload and a compression ratio of about 4 to 1. We compare the technique to three other encoding schemes, including a new, "one-pass", cosine transform encoder.