Because of catadioptric imaging

two points in the world with same distance will have different distance in omnidirectional image when they are projected to the periphery or center on the image plane.Thus

traditional definition of the neighborhood cannot be appropriate for omnidirectional images.In this paper

make use of ratio of resolution between different position in image

we propose a new system of neighborhood adapted to the omnidirectional images and deduce a new formula for calculating resolution of a catadioptric sensor.We show that this definition of neighborhood for catadioptric omnidirectional image conduce a more coincident result than traditional one in application of moving target detection base on Markov random fields.