Mosaicing of Camera-captured Documents Without Pose Restriction

In this paper we present an image mosaicing method for camera-captured documents. Our method is unique in not restricting the camera position, thus allowing greater flexibility than approaches using scanner or fixed-cameras. To accommodate for the perspective distortions introduced by varying poses, we implement a two step image registration process that accurately computes the projectivity between any two document images with an overlapping area that may be as small as 10%. In the overlapping area, we apply a sharpness based selection process to obtain seamless composition across the border and within. Experiments show that our approach can produce a very sharp, high resolution and accurate full page mosaic from small image patches of a document captured from unconstrained positions.