Acta Math. Acad. Paed. Nyíregyháziensis
15 (1999), 61-68

An algorithm using Walsh transformation for compressing typeset documents

Attila Fazekas and András Hajdu



In this paper the authors present an algorithm which can be used for compressing text documents, principally. The algorithm allows some loss of information, but the original digital image is compressed in a rather efficient way, so the result compressed data structure is suitable to be transmitted through some kind of telecommunication channel. The original document is assumed not to contain sophisticated typographical details, but text, and some simple graphics. The compression algorithm tries to recognize the text parts of the document and the result of a character recognition process is stored, instead of the graphic representation of the text. This character recognition part is based on Walsh transformation. The algorithm was tested in several cases, and proved itself to be pretty efficient and reliable for simple documents.


Mathematics Subject Classification. 68U10.

Key words and phrases. Image data compression, optical character recognition, Walsh transformation.

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