Reconstruction of 3D Surface and Restoration of Flat Document Image from Monocular Image Sequence

There is a strong demand for the digitization of books. To meet this demand, camera-based scanning systems are considered to be effective because they could work with the cameras built into mobile terminals. One promising technique proposed to speed up book digitization involves scanning a book while the user flips the pages. In this type of camera-based document image analysis, it is extremely important to rectify distorted images. In this paper, we propose a new method of reconstructing the 3D deformation and restoring a flat document image by utilizing a unique planar development property of a sheet of paper from a monocular image sequence captured while the paper is deformed. Our approach uses multiple input images and is based on the natural condition that a sheet of paper is a developable surface, enabling high-quality restoration without relying on the document structure. In the experiments, we tested the proposed method for the target application using images of different documents and different deformations, and demonstrated its effectiveness.