Automatic noise robust registration of radiographs for subtraction using strategic local correlation: an application to radiographs of dental implants.
Most of digital subtraction methods in dental radiography are based on registration using manual landmarks. We have developed an automatic registration method without using the manual selection of landmarks. By restricting a geometrical matching of images to a region of interest (ROI), we compare the cross-correlation coefficient only between the ROIs. The affine or perspective transform parameters satisfying maximum of cross-correlation between the local regions are searched iteratively by a fast searching strategy. The parameters are searched on the 14 scale image coarsely and then, the fine registration is performed on the original scale image. The developed method can match the images corrupted by Gaussian noise with the same accuracy for the images without any transform simulation. The registration accuracy of the perspective method shows a 17% improvement over the manual method. The application of the developed method to radiographs of dental implants provides an automatic noise robust registration with high accuracy in almost real time.
Yi
Won-Jin
WJ
Department of Oral and Maxillofacial Radiology, BK21, and Dental Research Institute, College of Dentistry, Seoul National University, 28, Yongon-Dong, Chongno-Gu, Seoul, 110-749, Republic of Korea.
Heo
Min-Suk
MS
Lee
Sam-Sun
SS
Choi
Soon-Chul
SC
Lee
Sun-Bok
SB
Huh
Kyung-Hoe
KH
D015921:Dental Implants; D006801:Humans; D011857:Radiographic Image Interpretation, Computer-Assisted; D011861:Radiography, Dental / Q000379:methods*; D013382:Subtraction Technique
D015921:Dental Implants