利用仿射几何特性提取图像中的仿射不变特征

Affine Invariant Feature Extraction Based on Affine Geometry

利用仿射几何的性质从图像中提取仿射不变特征,提出了扩展质心(extended centroid,EC)和仿射区域划分(affine region cutting,ARC)的概念,通过迭代ARC求得多个仿射区域的扩展质心序列,将扩展质心序列按一定规则组合成一系列三角形,然后根据仿射几何的性质,由各个三角形的面积构造不变特征。该不变特征提取方法具有速度快、简单灵活的特点,所构造的特征量对照度变化、噪声干扰、部分遮挡以及小角度3维旋转具有较好的稳定性,实验结果验证了该方法的有效性。

A new affine invariant feature extraction method based on the affine geometry property is presented in the paper. New conceptions named Extended Centroid（EC） and Affine Region Cutting（ARC） are firstly introduced. A series of ECs are then extracted by iterative ARC, and invariant features are constructed from the ratio of the area of the triangle which are formed with ECs. Compared with other affine invariant techniques, the ECARC based method shows good performance in computational complexity and stability to the illumination and 3D rotation in certain range.