中文摘要：

为了合理利用视觉关键词之间的空间关系，以提高基于视觉关键词的对象检索方法的准确度，提出一种利用仿射变换进行空间关系验证的算法．首先通过视觉关键词仿射协变的空间邻近特征集进行初步空间关系一致性匹配；然后计算对应仿射协变区块的多组可能的仿射变换矩阵，并选择满足区块匹配最多的变换矩阵作为对象与图像之间最终仿射变换矩阵，其中，仅利用一对协变区块来计算自由度为6的仿射变换的算法有效地提高了计算速度和鲁棒性；最后通过计算出的仿射变换矩阵来精确验证对象与图像之间的空间位置关系是否一致．实验结果表明，与现有方法相比，文中算法更鲁棒，能以较低的计算开销显著地提高基于对象的实时图像检索的准确度．

英文摘要：

A fast spatial verification scheme using affine transformations is proposed to improve the retrieval precision by exploiting proper spatial constraints among visual key words. Firstly, affine covariant neighborhoods of visual words are used to verify the spatial consistency. Secondly, a set of affine transformation matrices between the corresponding covariant regions is calculated, and the matrix with the most inliers is chosen as the best matching affine transformation matrix （BMATM）. In this step, only a single pair of corresponding affine covariant regions is used to calculate the 6 degree of freedom （DOF） affine transformation for acceleration. In the last step, the spatial consistency is verified by the BMATM. Experimental results show that this scheme is more robust, more accurate and faster in compare with the state of-the-art approaches.