Many algorithms in computer vision usually use a pin-hole camera model. An image is caused by both projective transform and the lens distortion as fish-eye lens or wide-angle lens have large distortion. Unlike the traditional methods which need much information of the scene

a novel approach using geometrical invariability of line to perform camera self-calibration from a single image is presented. In order to correct lens distortion and calculate vanishing point from the image

projective invariants are used: collinear points should be in the same line

Parallel line should be intersect at one point; metric invariant is used: the included angle of orthogonal straight lines should be rectangular. So camera lens distortion and internal parameters are calibrated. The result of emulation and real images are accurate and reliable with this method.