Fast trifocal tensor estimation using virtual parallax

We present a computationally efficient method for estimating the trifocal tensor corresponding to three images acquired by a freely moving camera. The proposed method represents projective space through a "plane + parallax" decomposition and employs a novel technique for estimating the homographies induced by a virtual 3D plane between successive image pairs. Knowledge of these homographies allows the corresponding camera projection matrices to be expressed in a common projective frame and, therefore, to be recovered directly. The trifocal tensor can then be recovered in a straightforward manner from the estimated projection matrices. Sample experimental results demonstrate that the method performs considerably faster compared to a state of the art method, without a serious loss in accuracy.