Bandwidth reduction and image distortion characteristics of the LMS image compression algorithm

The Least Mean Squares (LMS) Algorithm may be used to adapt the coefficients of an adaptive prediction filter for image source encoding. It is shown that if one allows a small amount of distortion in the received image, then the LMS algorithm allows a dramatic reduction in the required channel transmission bandwidth. Results are presented which show LMS provides up to a 1-2 bits per symbol reduction in transmitted bit rate (compared to DPCM) when distortion levels are approximately the same in both cases. Further, LMS can equivalently be used in fixed channel bandwidth environments to decrease the image distortion. When compared to results for fixed coefficient DPCM, one is able to reduce reconstructed image distortion by as much as 7-10 dB using LMS.