Image Registration Using Template Matching and Similarity Measures for Dental Radiograph

Dental radiographs are used to diagnose and treat dental diseases. For accurate diagnosis, geometrical registration of radiographs is required. In order to compare two dental radiographs prepared from the same part of teeth in different time intervals. It is necessary to register the locality of images, so that by removing deviations between the two images and finding a mapping function, local transitions, rotational and scale differences and even visual differences are corrected. In this paper, an X-ray dental image registration algorithm based on template matching and similarity measure is proposed. The proposed registration process is carried out in three stages. The first stage includes the automatic selection of a set of control points of the sensed image based on its features. In the second stage, displacement vectors of these control points are determined by comparing a template and normalized cross correlation (NCC) as a similarity measure. Full displacement vector field is then performed using these displacement vectors and the affine transformation function, and the final correction is carried out by changing the geometric shape of the reference image. The obtained results of the proposed algorithm show effectiveness of this algorithm in dental radiograph image registration.