Corner detection in fisheye images by modified Yin-Yang grid

We propose a framework to extend corner feature detection in standard rectangular images with less distortion to distorted circular images captured with fisheye lenses. To solve two problems of nonuniformity of spatial resolution and spherical polar coordinates singularity, our approach makes use of a modification in the Yin-Yang grid, which is an overset grid consisting of two latitude/longitude coordinate systems. The main contribution is to keep the use of existing corner detection programs. Experimental results on synthetic and real images demonstrate the effectiveness of our method.