A method and an apparatus for data compression suitable for the Markov model coding of mixed binary images including documents, diagrams, halftone images and photographs and comprising the first step of calculating an image statistic from an input binary image, the second step of performing area classification of the input binary image according to the image statistic and preparing area classification data and the third step of producing reference data to be used in the Markov model encoding. The reference data is composed of a first data portion corresponding to the area classification data and a second data portion composed of e.g. neighbouring or correlating picture values or predicted gray-level values. <IMAGE>
Method and apparatus for binary image data compression