利用2D射影变换求解空间复杂结构的3D不变量

3D不变量作为不随姿态、视点等成像条件变化而变化的特征参量，可以广泛应用于计算机视觉的多重领域．通过分析2D射影变换矩阵求解的多种可能性，由单纯基于点集对应的思路扩展到利用点集、线集、点、线组合等其它方法，从而拓宽了建立两射影平面对应关系的应用条件．由此提出了一种基于多种点线组合构造虚元素的方法，结合实元素和虚元素可以巧妙提取空间复杂结构下的多种3D不变量，以用于目标识别和描述当中．实验结果验证了方法的有效性。

COMPUTING 3D INVARIANTS OF COMPLICATED SPATIAL STRUCTURES BY USING 2D PROJECTIVE TRANSFORMATION

D invariant is a kind of feature parameter that can stay consistent along with the change of pose, view point or other imaging conditions. It can be used widely in computer vision. The approaches to calculation of 2D projective transformation matrix are extended from using points to using points, lines and point line groups. So the application conditions for describing the relationship between two projective planes become free and wide. From this, the extraction of virtual elements based on various kinds of point line groups are presented, and many kinds of 3D invariant of complicated spatial structures can be neatly extracted by combining real elements and virtual elements. These invariants can be used to object recognition and interpretation. The above methods have been verified by experiments.