A new technique to extract the 3D vision information of conicoids robustly from their gray level image is successfully developed in this paper.The closed mapping relationship between the 3 D position and attitude of a conicoid and its image contour is explicitly derived.The relationship can be applied to efficiently determining the position and attitude of a concoid from the conics robustly extracted from the gray level image by means of the technique mentioned in .The experiments have demonstrated that the technique is fast

efficient and robust.