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Preprocessing Method for Binary Image Compression Disclosure Number: IPCOM000039500D
Original Publication Date: 1987-Jun-01
Included in the Prior Art Database: 2005-Feb-01

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Toyokawa, K [+details]


This article describes a preprocessing method for binary image which is performed prior to a conventional compression process, such as MR (Modified Read) scheme. The preprocessing method realizes a high compression efficiency for a dither halftone image. The preprocessing method includes steps of classifying dither halftone areas from text/ graphic areas, executing an exclusive OR operation of a current dither halftone block and a preceding dither halftone block, and storing the result of the exclusive OR operation as data which represents the image of the current dither halftone block. (Image Omitted) Figs. 1A and 1B show operational steps of compression and decompression processes in the present method.