Exploiting Vector Fields for Geometric
Rectification of Distorted Document Images
Abstract. This paper proposes a segment-free method for geometric
rectification of a distorted document image captured by a hand-held
camera. The method can recover the 3D page shape by exploiting the
intrinsic vector fields of the image. Based on the assumption that the
curled page shape is a general cylindrical surface, we estimate the parameters related to the camera and the 3D shape model through weighted
majority voting on the vector fields. Then the spatial directrix of the
surface is recovered by solving an ordinary differential equation (ODE)
through the Euler method. Finally, the geometric distortions in images
can be rectified by flattening the estimated 3D page surface onto a plane.
Our method can exploit diverse types of visual cues available in a distorted document image to estimate its vector fields for 3D page shape
recovery. In comparison to the state-of-the-art methods, the great advantage is that it is a segment-free method and does not have to extract
curved text lines or textual blocks, which is still a very challenging problem especially for a distorted document image. Our method can therefore
be freely applied to document images with extremely complicated page
layouts and severe image quality degradation. Extensive experiments are
implemented to demonstrate the effectiveness of the proposed method