Binarizing Document Image Using Coplanar Prefilter

Liying Fan, Lixin Fan, Chew Lim Tan

Abstract: We propose a novel coplanar filter, which exploits the coplanarity of gray-level distribution of neighboring pixels, to pre-filter the document images. Experiments show that the proposed filter exhibits the following desired properties for document image binarization: 1) impulsive noise removal, 2) piecewise smoothing, and 3) sharp edge preservation.