Camera self calibration based on direct image alignment

We propose a camera self calibration method based on direct image alignment (DIA) for estimating camera parameters including lens-distortion components from planar scenes. We formulate a cost function without the inverse of the lens distortion function for avoiding the difficulty in the image alignment between two lens-distorted images. We also use a backward warp cost for improving the convergence instability due to inherent ambiguities in calibration parameters and blurring effects through image warps. We show our method leads to a comparable performance with the de-facto standard Matlab toolbox for non-self calibration, even though the proposed method is for self calibration.