An efficient image-registration method based on probability density and global parallax

This paper is concerned with the problem of image registration of video sequence, to meet the accuracy and real-time requirements for video analysis and processing. Despite of the existence of sophisticated registration algorithms, it is still problematic to register images precisely with low computation complexity due to the lack of stable features and effective matching method. In this paper, a probability density gradient based interest point detector is employed to extract stable point features precisely. And a robust technique, namely, global parallax histogram based filter is proposed to discard outliers in the initial candidate matches set found by classical correlation method. The registration matrix can then be accurately and precisely estimated using a well adapted criterion. Several field tests are performed on complex and challenging images to assess the performance, including comparison to conventional algorithms, and both inter-frame registration results and statistical analysis of video sequence. These simulations validate the improvement of proposed method in accuracy and efficiency, and the robustness against camera motions, illumination variations, acquirement conditions, moving objects and image noise.