图象匹配中的仿射透视近似

提出了在图象匹配中使用的一些新的仿射透视近似投影不变量。文中引进了点的仿射透视近似的概念，分析了线段的透视投影与其仿射透视近似间的最大相对误差，获得了一个有实用价值的距离三角形误差判决准则。基于此准则，研究了物体上同一空间平面中，平行线段长度比，同底面积比等仿射不变量，近似用作透视不变量的可能性。实验结果证实了分析的可靠性。

Affine-Perspective Approximation in Image Matching

This paper proposes some new affine-perspective approximate invariants that are used in image matching. In this paper we introduce the concept of the affine-perspective approximation for the perspective projection of a point on an object,and then through the further analysis of the maximum relative error between the perspective projection of a line segment on the object and its affine-perspective approximation,obtain a practically valuable 'Distance Triangle Error Decision Rule' (DTEDR). Starting from the rule, we invastigate the possibility of using some affine invariants, e. g. on a plane of a given object, the ratio of lengths of two parallel line segments or the ratio of areas with a comman base etc., are taken as approximate perspective invariants. Experimental results have verified the reliability of our analysis.