A binary image preprocessor for document quality improvement and data reduction

A new binary image-enhancement operation is proposed to suppress noise in documents, introduced, e.g., by poor-quality copying. As opposed to approaches previously published, the new technique does not erode characters, symbols, drawing elements, etc, and thus improves the intelligibility of documents. In addition, it is shown that the new preprocessing method reduces significantly the data volume necessary to represent documents in compressed form. Finally, a low-cost hardware implementation is proposed, suitable of being integrated, e.g., in future scanning devices.