A Simple Predictive Transform Coder for Images

In this paper a simple predictive transform coder is proposed for the processing of images. The coder is intrafield and predicts the coefficients of a two-dimensional Hadamard transform based on the past pels immediately surrounding the transformed block. The cost and performance of the new coder compares well with that of other techniques. For example, a predictive transform coder acting on 2×2 picture blocks and operating at an average bit rate of 2 bits/pel is found to yield significantly better picture quality than that derived from a 2×2 or even a 4×4 Hadamard coder. Also, just as important, the physical implementation of this coder requires from two to three times the number of on-line operations required by a 2×2 Hadamard coder and 1/4 to 1/3 that of a 4×4 Hadamard coder.