一种新的仿射不变特征及其在平面曲线匹配中的应用

A new affine invariant feature and its application in planar curves-matching

构造了一种新的仿射变换不变特征,提出了一种适合于仿射变换的曲线匹配算法。首先将整个轮廓区域进行仿射区域划分,得到一系列子区域质心点;然后将质心和子区域的质心点按规则构成三角形,计算三角形的面积比序列,并将其规范化,构造新的仿射不变特征。在该不变特征的基础上设计新的识别向量和差异度度量函数,通过计算待识别目标与模型曲线之间的差异度来判断是否匹配。理论分析和仿真实验表明,本文方法能成功用于仿射变换下的曲线匹配中,并且对于轮廓相似的物体也能按照差异度大小分别识别出来。

A new invariant feature under affine transformation is given. And then, a new method for matching planar curves under affine transformation is proposed in this paper. First,the affine region is divided for obtaining a series of sub-region＇s centroids. Then the triangles are constituted by using the whole contour＇s centroid and sub-region＇s centroids. The sequences of triangles＇ area ratios are calculated and normalized. On the basis of the new invariant feature, a new recognition vector matrix is defined, and a different measurement function is defined too. Finally, the different measurement value between model curve and object curve is calculated,which can be employed to judge whether the model and object are matched. Theory analysis and experimental results show that the method is feasible, which can not only match different curves but also distinguish the objects with a similar shape according to different measurement values.