Mirror Invariant Matching between Catadioptric Omnidirectional and Perspective Images

For catadioptric imaging may arise mirror effect between omnidirectional image and perspective image, and scale invariant feature transform algorithm is not invariant to image mirroring. This paper proposes flip horizontally perspective image, and then matches separately the original image and the flipped image with omnidirectional image, takes a better match as the final result to achieve the mirror invariant. For the ring distortion of the omnidirectional image, the perspective image is transformed to the fan-shaped image before the matching, and two methods are provided to transform the perspective image to the fan-shaped image. Experimental results on the real image show, after the perspective image is transformed to the fan-shaped image and then match with omnidirectional images, the total number of matching points is increased , while the number of the wrong matching points is reduced, matching results are better than one without the transformation.