Dewarping Machine Printed Documents of Gurmukhi Script

Abstract

During the scanning of bound documents, some part of the document image is curled near the corners or near the binding resulting in bending of text lines. This hard to tackle distortion makes recognition very difficult. A method has been proposed for estimation and removal of line bending deformations introduced in document images during the process of scanning. The estimation of bend involves determining the side of the document on which curl is present and direction of the bend. The method has been tested on varieties of printed document images of Gurmukhi containing the bent text-lines at page borders. The method consists of three stages. In the first stage, a decision methodology is proposed to locate the site of deformation and the direction of deformation. An elliptical approximation model is derived to estimate the amount of deformation in the second stage. Finally, a transformation process brings out the correction. Experiments show that the method developed works well under conditions where pixel distribution is uniform.