Frame stitching in human oral cavity environment using intraoral camera

Abstract

The present invention is a method to stitch images of human teeth that are captured by an intraoral camera. Oral dental applications based on visual data pose various challenges such as low lighting conditions and saliva. Herein we describe a stitching algorithm of low-texture/low-resolution imaging. First, normals of tooth surface are extracted using shape from shading. An algorithm to rectify the imprecise values of the surface normal due to the oral environment is applied and normal maps generated. Second, the normal maps are used to detect, extract and match the corresponding features. Finally, to enhance the stitching process for these unidealized data, normal maps are used to estimate as-projective-as-possible warps. The proposed approach outperforms the state-of-the-art auto-stitching approach and shows a better performance in such cases of low-texture regions.