Emgu 学习(3) 绘图，使用鼠标绘图，使用trackbar

绘图

    class Program
    {
        static void Main(String[] args)
        {
            Mat img = new Mat(600, 400, DepthType.Cv8U, 3);
            img.SetTo(new Bgr(0, 0, 0).MCvScalar);
            //绘制一条黄色，线宽为4 的反锯齿线段
            CvInvoke.Line(img, new Point(10, 10), new Point(100, 250), new MCvScalar(0, 255, 255),4,LineType.AntiAlias);
            //绘制圆心为200,100，半径为50，线宽为15的红色空心圆
            CvInvoke.Circle(img, new Point(200, 100), 50, new MCvScalar(0, 0, 255), 15, LineType.AntiAlias);
            //绘制左上角200,300宽高为150,100的绿色矩形框
            CvInvoke.Rectangle(img, new Rectangle(200, 300, 150, 100), new MCvScalar(0, 255, 0), 1);
            //绘制中心为200,200，大小为150,120，旋转40度，颜色为cyan的椭圆
            CvInvoke.Ellipse(img, new RotatedRect(new Point(200, 200), new Size(150, 120), 40), new MCvScalar(255, 255, 0), 3);
            //绘制文字
            CvInvoke.PutText(img, "CTC", new Point(100, 100), FontFace.HersheyComplex, 3, new MCvScalar(0, 255, 255), 2);

            
            CvInvoke.Imshow("draw", img);
            CvInvoke.WaitKey(0);

        }
    }

效果

使用鼠标绘制矩形

 效果如下，使用鼠标中键拖拉矩形框。

中间黑色的控件是ImageBox，没有缩放

        Point pt = new Point();
        Mat frame = null;
        public Form1()
        {
            InitializeComponent();
            frame=new Mat(imageBox1.Height,imageBox1.Width, DepthType.Cv8U, 3);
            frame.SetTo(new Bgr(0, 0, 0).MCvScalar);
            CvInvoke.Line(frame, new Point(10, 10), new Point(100, 250), new MCvScalar(0, 255, 255), 4, LineType.AntiAlias);
            Application.Idle += Run;
        }

        private void Run(object sender,EventArgs e)
        {
            imageBox1.Image = frame;
        }

        private void imageBox1_MouseDown(object sender, MouseEventArgs e)
        {
            pt.X = e.X;
            pt.Y = e.Y;
        }

        private void imageBox1_MouseUp(object sender, MouseEventArgs e)
        {
            CvInvoke.Rectangle(frame, new Rectangle(pt.X, pt.Y, e.X-pt.X, e.Y-pt.Y), new MCvScalar(0, 255, 0), 1);
        }
    }

 使用Trackbar调整数值threshold处理

    public partial class Form1 : Form
    {
       
        Mat src = null;
        Mat dst = new Mat();
        string path=@"C:UsersdellPicturesmach.jpg";
        public Form1()
        {
            InitializeComponent();
            src = CvInvoke.Imread(path);
            imageBox1.Image = src;

        }

        private void trackBar1_ValueChanged(object sender, EventArgs e)
        {
            int value = trackBar1.Value;
            CvInvoke.Threshold(src, dst, value, 255, ThresholdType.Binary);
            imageBox1.Image = dst;
        }


    }