Semi-automatic metric reconstruction of buildings from self-calibration: preliminary results on the evaluation of a linear camera self-calibration method

We investigate the linear self-calibration method proposed by Newsam et al. (1996) for our project on 3D reconstruction of architectural buildings. This self-calibration method assumes that the principal point is known, the camera has square pixels and has no skew. It allows 3D shape to be reconstructed from two images while giving the camera the freedom to vary its focal length. In this paper, we evaluate the focal lengths obtained from their method with both synthetic data and real data. In real data where known 3D data are available, Tsai´s (1987) calibration method is used for comparison. Our experimental results show that the focal lengths from the two methods differed by less than 5% and the reconstructed 3D shape was very good in that angles were well preserved