Registration Of Substation Remote Infrared Images

The substation remote monitoring system which based on infrared thermal images is a new kind of monitoring----visual surveillance. The system can carry out real time online monitoring and fault diagnosis to multiple substation equipments simultaneously and continuously, it cuts down the out-of-order equipments or keeps monitoring them. Thus ensures the safe operation of electrical equipments. However, the acquired sequence infrared images have position deviation, this disable the system normally monitoring the interested equipment. Thus the deviated images need to be registered.In this paper, we have researched the basic framework and common methods of image registration. And adopt feature-based image registration method according to the character of our images. The writer firstly improved the classical Harris-corner matching approach, using the phase correlation method which based Fourier transform to acquire the main direction of movement between two images. This greatly reduced the searching area and computing time of matching, and could eliminate false matching points. Experiments show that this algorithm has some applicability and high matching accuracy. Secondly, this article presented a new method—SIFT algorithm which used in image registration and pattern recognition recently. We also have improved the matching strategy of the algorithm, using the phase correlation again to guide the matching step to acquire a small searching area and consuming time. And controlled the matching points within five to ten by adjusting the ratio of matching threshold, this greatly improved the efficiency of registration. Combine these two methods, the improved SIFT algorithm demonstrated better performance in applicability, accuracy and consuming time.