3D geometrical modeling is a hot and difficult problem in computer vision.the parameter equation of quadric patch is fitted by adopting the eigenvector estimate method of linear least squares.Second the extracton technology is expounded for differential coefficient invariable geometry attributes,such as curvature average value and entropy of curvature distribution,and the movement invariable geometry attributes,such as 0-order and 2-order 3D movement invariant of quadric patch.Third expression m...