BINARY REPRESENTATION OF MIXED DOCUMENTS (TEXT/GRAPHIC/IMAGE) THAT COMPRESSES.

Abstract

The authors describe a processing algorithm which processes multilevel scans of mixed documents, containing continuous tone images as well as text and line art, and produces good-quality binary documents which compress well when operated on by run-length-based coding schemes such as the CCITT standard MH (modified Hoffman). The binary documents produced have sharp edges in the text areas and accurately represent tone, free of contours, in continuous tone areas. The overall grayness of the original documents can be recovered from the halftone documents, permitting them to be converted to other representations more appropriate for specific output devices. The simplicity of the algorithm allows it to work in a real-time environment and it can be easily implemented on various signal processors and microprocessors.