An efficient registration method for partially overlapping images

AbstractIn this paper, a method for accelerating registration of partially overlapping images is presented. Image registration is a fundamental problem in image processing and computer vision. Numerous studies have been done on this subject and can satisfy most of engineering application requirements. However, the registration processing is very time-consuming when the images are very large. So, time-saving methods are desirable.The proposed method, which is based on a feature-based method, concerns the computational cost of registration of partially overlapping images. The feature-based method generally contains four steps--features detecting, features matching, estimation of the homography and image warping and blending. The new method includes two stages. In the first stage, overlapping areas are rapidly estimated from the low-resolution correspondences of candidate images by a SIFT-based method. In the second stage, a homography between the image pairs is calculated by the same SIFT-based method, which involves only the overlapping areas between a target image and a reference image. Then the target image is warped and blended with the reference image. The experimental results demonstrated that our proposed method can reduce the computational cost to 10%∼30% of that of the SIFT-based homographic estimation (SHE) methods with little compromise in accuracy