仿射不变的中心投影

 考虑将区域和轮廓类不变特征提取算法结合:利用中心投影将目标转化为闭曲线,对闭曲线运用轮廓类方法提取不变特征.证明了图像经中心投影所得闭曲线保持仿射变换的结论.介绍了一种利用小波变换进行仿射不变特征提取的算法.对一些汉字、26个大写英文字母等的实验结果表明结论的有效性,与传统方法相比该算法对噪声具有较强的鲁棒性.

Affine Invariance of Central Projection Transformation

A method is proposed by combining contour-based methods with region-based methods.A closed contour is derived from the object by central projection transformation,and invariant features are extracted from this closed contour.The affine invariance of the closed curve derived by central projection transformation has been proved.An algorithm is provided to extract affine invariant features by employing stationary wavelet transform.Some Chinese characters and 26 capital letters are used to evaluate the proposed method.Experimental results show that the proposed method can efficiently extract invariant features.Compared to traditional methods,the proposed method is robust to noise.