9.2，绘制一个圆

Mat mat = new Mat(@"I:\OpenCvSharp学习\Temp\Test\1.bmp", ImreadModes.AnyColor);
int width = mat.Width;
int heigth = mat.Height;
Point point1 = new Point(width / 2, heigth / 2);
Window window1 = new Window("源图像", WindowMode.Normal, mat);
Cv2.Circle(mat, point1, 40, Scalar.Red, 1,LineTypes.Link8,0) ;
Window window2 = new Window("处理1", WindowMode.Normal, mat);
Cv2.WaitKey(0);

//参数说明:
//重载1:
public static void Circle(InputOutputArray img, 
                          Point center, 
                          int radius, 
                          Scalar color, 
                          int thickness = 1, 
                          ineTypes lineType = LineTypes.Link8, 
                          int shift = 0);