提出了用3个向量描述Harris角点方向特征的方法，该算法首先用Harris角点检测得到特征点，并把SIFT算法中使用的特征描述方法引入到特征点描述中；然后利用欧氏距离对点特征进行匹配；提出一种简单高效的排除错误匹配的方法。该算法对数字城市中序列图像匹配具有光照强度、平移、旋转不变性。实验结果表明，该算法匹配准确率较高，具有实用价值。

Firstly, the Harris corner detector is used to detect corners, a method to describe the direction character of the corners is given and the keypoint descriptor of SIFT(scale invariant feature transform) is introduced in this method. Secondly, Euclidean distance is performed to get exact matching in the corner set. Finally, an easy and effective method to avoid wrong matches is discussed. This method is effective on brightness invariant, movement invariant and rotation invariant in the matching of digital city image sequences. This method is proved to be effective by realistic experiments, and of high practicability.