Document image skew detection algorithm based on geometric constraint
基于几何约束的文本图像倾斜角检测算法

For the problem of detecting the angle of the document image, this paper proposed a new skew detection algorithm based on the geometric constraint of the document image. The algorithm got the lowest pixels of a set of characters by the method of region-labeling-automata. It evaluated the skew angle by applying moment calculation, and described the method to get characters in one text-line in detail. The experimental results show that the efficiency and the accuracy are both improved by this algorithm, what's more, the document images with large skew angle and the document images containing a few characters can also be treated by this algorithm. Therefore, the document images of various languages, including English, Chinese and Japanese can be validly treated by this algorithm.