本文主要介绍下opencv中怎样使用hog算法，因为在opencv中已经集成了hog这个类。其实使用起来是很简单的，从后面的代码就可以看出来。本文参考的资料为opencv自带的sample。

　　开发环境：opencv2.4.2+Qt4.8.2+ubuntu12.04+QtCreator2.5.

　　实验功能：

　　单击Open Image按钮，选择需要进行人检测的一张图片，确定后自动显示出来。该图片的大小没限制。

　　单击People Detect按钮，则程序会自动对该图片进行行人检测，且将检测到的效果显示出来，即用1个矩形框将行人框出来。

　　单击Close按钮，退出程序。-This article describes how to use the next opencv the hog algorithm has been integrated in the opencv hog this. In fact, it is easy to use, can be seen from the code behind. Reference information in this article comes with sample for opencv. Development environment: opencv2.4.2+Qt4.8.2+ubuntu12.04+QtCreator2.5 experimental feature: Click the Open Image button to select a picture of the need for people detection, to determine automatically displayed. No limit on the size of the picture. Click the People Detect button, the program automatically the picture of pedestrian detection, and the detected results show a rectangular box, pedestrian box out. Click the Close button to exit the program.