【摘要】 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。本文从射影几何中的最基本的不变量──交比出发，导出了共面五条直线的所有射影不变量之间的相互关系，通过这些关系，把共面五条直线射影不变量分成两两独立的五类，并以此为基础，推导了两个相互独立的，与直线排列顺序无关的共面五条直线的联合射影不变量。更多还原

【Abstract】 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.更多还原