说明：  基于对话框中picture控件绘制直方图 是在视频流中截取出的一帧图像进行直方图统计，如果不停的截取，将形成动态的直方图，该函数是基于OpenCV中视频帧中调用，故参数是IplImage类型的
(Based on dialog box picture control drawing histogram is in streaming video capture a frame of image histogram statistics, if intercepted, will form a dynamic histogram, this function is based on OpenCV video frame in the call, so the parameter is the IplImage type )