<title>Highly efficient arithmetic coding method for document images</title>

Abstract

We propose a highly efficient arithmetic coding method for document images. In the arithmetic coding, series of symbols to be coded are mapped on a coordinate of a numerical line segment which corresponds to a coding space. By using a priori knowledge and statistical knowledge we can improve coding efficiency on that mapping procedure. We describe highly efficient arithmetic coding algorithm and simulation results for document images including characters, figures and pseudo gray-scale images. These document images are dominant parts of facsimile documents. The restrictions have been put in the procedure of arithmetic coding. Simulation results by using CCITT standard documents and pseudo gray-scale images show that our coder achieves about 10% - 23% reduction of total amount of code data in comparison with conventional arithmetic coders.