"Cascade coding," a technique of double coding an image is introduced in this paper. Blocks of the image are first transform-coded and the retained coefficients of the transform are then quantized by a Block Truncation Coding C BTC) algorithm for transmission or storage. Upon reception or recall, the quantized transform coefficients are used in the inverse transform to reconstruct the image. The new method combines the spatial correlation characteristics of the transform methods with the ease of implementation of the BTC. Illustrations presented here on sub-bit image coding, shows it to perform consistently better than straight Cosine Transform (DCI') coding.

Date Published: 1 June 1990
PDF: 12 pages
Proc. SPIE 1244, Image Processing Algorithms and Techniques, (1 June 1990); doi: 10.1117/12.19492

Published in SPIE Proceedings Vol. 1244:
Image Processing Algorithms and Techniques
Robert J. Moorhead II; Keith S. Pennington, Editor(s)