各向异性非刚性形变局部不变特征研究.pdfVIP

学兔兔 第3l卷 第1期 仪 器 仪 表 学 报 、，0l_3l No．1 2010年 1月 Chinese Journal of Scientitic Instrument Jan．2010 各向异性非刚性形变局部不变特征研究术 龚卫国，童玉娟，李正浩 (重庆大学光电技术及系统教育部重点实验室 重庆 400044) 摘 要：当前多数局部不变特征算法主要针对刚性形变的图像匹配问题，但非刚性形变普遍存在且多数表现为各向互异。提 出一种面向各向异性非刚性形变的局部不变特征算法。本算法对最稳定极值区域进行同性化处理，使其各向形变在 定程度 上趋于同性且不受方向性影响，然后将图像投影到二维空间中，并通过调整外观权值获得形变不变的测地距离，最后建立各 向异性测地距离灰度直方图 (AGIH)描述符，使本算法进 一步适应各向异性的微小形变。验证实验表明，在非刚性形变情 况下，与SIFt算法、GIH算法相比，本算法在相同的错误匹配率的情况下，正确检测率平均提高了10．65％。 关键词：局部不变特征；非刚性形变；各向同性；各向异性；AGIH描述符 中图分类号：TP391．41 文献标识码：A 国家标准学科分类代码：520．6040 Research on local invariant features for anisotropic non—rigid deformation Gong Weiguo，Tong Yujuan，Li Zhenghao (Key Labfor Opto—electronic Technology and System ofMinistry ofEducation，Chongqing University,Chongqing 400044．China) Abstract：Recently,the research work on locaJ Invariant features mainly focuses on obtaining the lnvarlance to rigid deformation．HoweveL the intrinsic appearance of an object under various view conditions is of the non—rigid deformation，especially the anisotropic one．Therefore，we propose a method using anisotropic non—rigid deform a— tion invariant features．First，we conduct an isotropic deform ation on the Maximally Stable Extremal Region，and rotate the corresponding pairs to the same orientation．Then，the original image is projected into 3D space．With the increase of the aspect weight，numerous sets of deform ation invariant geodesic distance are obtained．At last， the Anisotropic Geodesic--Intensity Histogram is adopted as a non--rigid deform ation invariant local descriptor to make the proposed algorithm fit anisotropic small deform ation．Evaluations have been conducted on the non—rigid deform atio