共面五条直线的联合射影不变量

在计算机视觉中，共面五条直线的射影不变量已有非常重要的应用。但是由于共面五条直线射影不变量的形式很多，而且这些不变量和直线的排列顺序有关，这给不同图像中的不变量的匹配带来很大的困难。

Joint Projective Invariants for Five Coplanar Lines

Projective invariants for five coplanar lines have found many important applications in computer vision. Since there are many invariants for five coplanar lines and these invariants are relative to order of the lines, it is very difficult process to match the invariants from diffierent views. In this paper, we first derive the relations among all the projective invariants for five coplanar lines by using cross-ratio; then, we divide these projective invariants into five classes, any two of which being independent of each other; upon this, we derive two joint projective invariants for five coplanar lines which are independent of each other and irrelative to the order of the lines.