Local Retransmission Of Compressed Imagery Data
Clifford Reader, Wen-Hsiung Chen · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1978
Application of image compression to a given transmission problem involves trades between such factors as output quality, compression ratio and complexity of implementation. One specific case of interest for this discussion is "trunk-line" transmission, where a wide-band link is available and the overriding concern is preservation of image quality. In such a case complexity of implementation is of lesser concern, allowing the use of adaptive transform coding, but of sufficient concern that the adaptivity is constrained--coding bit maps are selected from a predetermined set of reasonable size, rather than being generated on a per image basis.(1) The question which arises is how to forward such data over a local link. Such a link will be of low or very low data rate, the coding and decoding must be as simple as is possible, quality is of lesser importance, though only because such is forced by low rate transmission and it can be assumed that no modification of the trunk-line transmission can be entertained solely to support local retransmission. This paper describes a method of approach to this problem with a technique called bit truncation.