一种采用HOG特征的直线段提取方法

直线段特征是广泛应用于图像分析与处理领域的一种特征，直线段提取是基于特征的模式识别和图像匹配的一个重要步骤，直线段提取方法的优劣直接影响到高层次图像处理的复杂度和处理的效果。针对目前直线段提取方法中存在的直线段端点不准确和直线段断裂问题，提出了一种新的基于HOG特征的直线段提取方法。该方法利用矩阵的行、列积分运算实现对原始图像特定方向直线段的投影，根据矩形函数的一阶导数性质将确定直线段端点位置的问题转化为对列方向向量的求导问题，从而更能有效提取出图像中的直线段。理论分析和实验结果表明:该方法能够快速、准确地提取直线段，在一定程度上解决了经典方法中直线段断裂及端点不准确问题。

Extracting line segments method with HOG feature

Line segment feature is widely used in the field of image analysis and processing, and line segment extraction is an important step in pattern recognition and image matching which are feature-based. The pros and cons of the line segment extraction method directly affects the complexity and the processing effects of high-level image processing. However, there were some problems in most of the current line segments extraction methods. For instance, the endpoints of the extracted line segment were not accurate enough and the extracted line segments were always discontinuous. A HOG-feature-based approach was represented to overcome the above two problems. In order to extract line segments efficiently, in this method, the integration on rows and columns of a matrix was used to realize the projection of line segments with particular direction in the original image. And then with the application of the property of the rectangular function's first derivative, the line-segment endpoints positions were determined via the column vector's derivative. Theoretical analysis and the results of experiments verified that this method can not only extract straight segments accurately, but also solve the straight segment fracture and endpoints inaccurate problems existing in the classic methods to some extent.