Traditional image rectification mainly aims to minimizing the least-squares distance between the matching points, however, the rectification process may cause great geometric distortion, which not only makes it impossible to offer information for 3-dimensional reconstruction, but also results in extra errors. An improved algorithm was proposed which minimizes the distortion by combining a newly developed projective transform with a properly chosen shearing transform. Firstly, projective transformation was developed to make the polar lines of two images align to the same direction. Secondly, shear transformation was introduced to ensure the image aspect ratio remain constant. Experimental result demonstrated that the proposed method is quite robust and well qualified to the rectification for 3D reconstruction.
