Improvements to the PCS algorithm for binary images

Abstract

Progressive coding1 for image data is the focus of current standardization activity within the CCITT and ISO organizations. Recently, a Joint Bi-level Image experts Group (JBIG) has been formed by these two organizations to study the question of progressive coding for bi-level image data. The point of departure for this work is the PCS algorithm for binary images described in ISO/CCITT standards meetings by Endoh and Yamazaki2, in which they added the use of arithmetic coding3 to previous proposals. Our paper summarizes some enhancements that can be made to this PCS scheme by improving the application of adaptive binary arithmetic coding (ABAC) technology. In particular, the "Q-coder" form of ABAC technology is used4 which was recently featured in the November 1988 issue of the IBM Journal of Research and Development5.