A high-speed pyramid image coding algorithm for a VLSI implementation

A nonseparable pyramid method based on a wavelet expansion is developed for image coding. It achieves high compression rates and at the same time allows a very efficient algorithmic implementation. In particular it uses only two additions and a shift (division by 2) for each image pixel during coding or decoding. Because the operations needed are mostly independent of each other and have a high degree of regularity, it is also possible to design very-large-scale integration (VLSI) hardware to perform this operation using an array of simple basic cells. For a typical 513×513 image one can achieve a peak signal-to-noise ratio of 30 dB with an entropy of 0.133 b/pixel. Transmitted coefficient values can be encoded with pulse code modulation to allow for simpler hardware while still requiring only 0.385 b/pixel, giving a very simple overall coding system