In this paper, we describe a new technique for encoding transform coefficients for error-free image compression with very little overhead in transmitting the error images. In traditional schemes for error-free transform coding, a fixed total number of bits is allocated for encoding the transform coefficients, and the difference image is encoded by a lossless encoding method. The total number of bits allocated to encode the transform coefficients is varied until the total average bit rate is minimized. In the present scheme, the quantization error for each transform coefficient is monitored, and additional bits are allocated to reduce this quantization error to less than a pre- specified maximum value. It is shown that the reconstructed image from transform coefficients quantized using this scheme will consist of only a negligible number of pixels in error by more than the pre-specified maximum value. This results in very little overhead for encoding the error image. The results of application of this method on a standard image and digitized mammograms are presented.
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