Retinal image registration based on salient feature regions.

Retinal image registration is essential and crucial for ophthalmologists to diagnose various diseases. A great number of methods have been developed to solve this problem, however, fast and accurate retinal image registration is still a challenging problem since the great content complexity and low image quality of the unhealthy retina. This paper provides a new retinal image registration method based on salient feature regions (SFR). We first extract the SFR in each image based on a well defined region saliency metric. Next, SFR are matched by using an innovative local feature descriptor. Then we register those matched SFR using local rigid transformation. Finally, we register the two images adopting global second order polynomial transformation with locally rigid registered region centers as control points. Experimental results prove that our method is very fast and accurate, especially quite effective for the low quality retinal images registration.