METHOD FOR IMPROVING DICTIONARY BASE COMPRESSION BY RASTER DATA SEQUENCING

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for the compression of an electronic document and its compression releasing granting requests for improved compression and the reduction of history memory size. SOLUTION: The reception of a scanning-line sequenced raster document which sequences raster data and the compression of data by a lossless dictionary compressing method are included. The sequencing of the raster data results in the correlativity of pixel data between scanning lines and the compression is improved. This sequencing decreases the size request of a history window of a slide window dictionary compressing method.