A DOCUMENT RECTIFICATION APPROACH DEALING WITH BOTH PERSPECTIVE DISTORTION AND WARPING BASED ON TEXT FLOW CURVE FITTING

Abstract

In this paper, we propose a coordinate transform model and document rectification process for book dewarping. This model can handle both perspective distortion and book surface warping problems. The main idea is to find the boundary of a region, which is a rectangle on a flat surface before warping and using the correspondence between the warped boundary and the original rectangle sides to map each pixel in the warped region into the rectangle. On a book page, two text lines and the left and right boundaries of a text region form a rectangle before warping. Therefore, we detect two text flow curves and text region boundaries on the left and right sides on a warped image and use the two curves and two line segments to do the transformation. The experimental results illustrate the effectiveness of our proposed book dewarping approach.