Estimating fisheye camera parameters from homography

Abstract

This paper presents a method to linearly estimate fisheye camera model parameters from the homography induced by the space plane between two fisheye images. The homography is firstly calculated by using four feature points, instead of three points on the same line, in the fisheye image. And the constraint on the model parameters of fisheye camera can be derived from the homography under the assumption that fisheye camera model is a polynomial model. Then the model parameters for different order polynomials are computed. The proposed technique requires only multiple fisheye images to include a planar scene and need not a priori knowledge of 3D coordinate of the planar scene. Experimental results with synthetic data and real fisheye images demonstrate the validity of our method. The method can also be extended to fisheye image of other planar scene excluding the planar calibration object.