Digitalisation of Warped Documents Supported by 3D-Surface Reconstruction

Abstract

The high quality digitalisation of warped documents is still a big problem for most scanner technologies. The presented work is a contribution to develop a new technique handling this problem. Basic principle of the proposed method is a special kind of light section, that works with a comparatively very broad stripe lighting by using one additional matrix camera. We can reconstruct the 3d-surface of the document by simple capturing an image sequence of the stripe lighting of a common book scanner during the scanning process. Based on a surface model we transform the warped document in a plane. Result is the two-dimensional output being a nearly distortion-free digital copy of the original warped document.