C# opencvSharp实现鼠标移动选择感兴趣区域(ROI)

C# opencvSharp实现鼠标移动选择感兴趣区域(ROI)主要通过鼠标响应事件来实现。

1.鼠标按下响应 MouseDown()

获取鼠标按下的开始坐标。

        private void pictureBox1_MouseDown(object sender, MouseEventArgs e)
        {
     
            RectStartPoint = e.Location; //获得鼠标按下的pictureBox上坐标
            Invalidate();
            blnDraw = true;//判断标志
        }

2.鼠标移动响应 MouseMove()

获得感兴趣区域框大小，显示感兴趣区域框以及坐标转换到原图像上。

private void pictureBox1_MouseMove(object sender, MouseEventArgs e)
        {
     
            if (blnDraw)
            {
      
                if (e.Button != MouseButtons.Left)//判断是否按下左键
                {
     
                    return;
                }
                    
                System.Drawing.Point tempEndPoint = e.Location; //记录框的位置和大小
                //pictureBox上开始点坐标
                Rect.Location = new System.Drawing.Point(
                Math.Min(RectStartPoint.X, tempEndPoint.X),
                Math.Min(RectStartPoint.Y, tempEndPoint.Y));
                //pictureBox上矩形大小
                Rect.Size = new System.Drawing.Size(
                Math.Abs(RectStartPoint.X - tempEndPoint.X),
                Math.Abs(RectStartPoint.Y - tempEndPoint.Y));
                pictureBox1.Invalidate();


                // 最后点位置
                int X0, Y0;
                Utilities.ConvertCoordinates(pictureBox1, out X0, out Y0, e.X, e.Y);
               
                //在控件中
                textBox1.Text = Convert.ToString("pictureBox最后点坐标" + e.X + "  ," + e.Y); //pictureBox 上终点坐标
                textBox2.Text = Convert.ToString("pictureBox开始点坐标" + Rect.X + "  ," + Rect.Y); //开始点坐标
                textBox3.Text = Convert.ToString("pictureBox的Width" + Rect.Width + "  ," + Rect.Height);//大小
 				
                //Create ROI 感兴趣区域
                Utilities.ConvertCoordinates(pictureBox1, out X0, out Y0, RectStartPoint.X, RectStartPoint.Y);
                int X1, Y1;
                Utilities.ConvertCoordinates(pictureBox1, out X1, out Y1, tempEndPoint.X, tempEndPoint.Y);
                //感兴趣区域 左上点坐标-宽-高
                RealImageRect.Location = new System.Drawing.Point(
                    Math.Min(X0, X1),
                    Math.Min(Y0, Y1));
                RealImageRect.Size = new System.Drawing.Size(
                    Math.Abs(X0 - X1),
                    Math.Abs(Y0 - Y1));
				textBox4.Text = "原图像上最后点坐标: X:" + X0 + "  Y:" + Y0;
                textBox5.Text = "原图像上RealImageRect: X:" + RealImageRect.X + "  Y:" + RealImageRect.Y; // 原图像-左上点坐标
                textBox6.Text = "原图像上RealImageRectSize: X:" + RealImageRect.Width + "  Y:" + RealImageRect.Height; // 原图像-大小


                Rect tmp_Rect = new Rect(RealImageRect.X,RealImageRect.Y, RealImageRect.Width, RealImageRect.Height);
                ImageROI = new Mat(img, tmp_Rect);//新建一个mat，把roi内的图像加载到里面去。
                //Cv2.ImWrite("4.jpg",ImageROI);  //保存         
            }
        }

3.鼠标抬起响应 MouseUp()

将感兴趣区域在pictureBox2控件上显示。

        private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
        {
     
            // mouseUp 结束以后 将图像显示在pictureBox2控件中
            pictureBox2.Image = ImageROI.ToBitmap();
            /***************************************/
            blnDraw = false; //结束绘制            
        }

4.重绘响应 Paint()

感兴趣的框的绘制。

        private void pictureBox1_Paint(object sender, PaintEventArgs e)
        {
     
            if (blnDraw)
            {
     
                if (pictureBox1.Image != null)
                {
     
                    if (Rect != null && Rect.Width > 0 && Rect.Height > 0)
                    {
     
                        e.Graphics.DrawRectangle(new Pen(Color.Red, 1), Rect);//重新绘制颜色为红色
                    }
                }
            }
        }

5.坐标转换

在本pictureBox 属性中sizeMode选择为 StretchImage,输入pictureBox控件上坐标转换为图像上实际的大小。

 public class Utilities
    {
     
        //坐标转换
        /**************************************
        * 图片左边转换，
        * Input输入: pictureBox 坐标X，Y
        * Output输出: Image 图像上对应的坐标
        **************************************/
        public static void ConvertCoordinates(PictureBox pic,
            out int X0, out int Y0, int x, int y)
        {
     
            int pic_hgt = pic.ClientSize.Height;
            int pic_wid = pic.ClientSize.Width;
            int img_hgt = pic.Image.Height;
            int img_wid = pic.Image.Width;

            X0 = x;
            Y0 = y;
            switch (pic.SizeMode)
            {
     
                case PictureBoxSizeMode.AutoSize:
                case PictureBoxSizeMode.StretchImage:
                    X0 = (int)(img_wid * x / (float)pic_wid);
                    Y0 = (int)(img_hgt * y / (float)pic_hgt);
                    break;
            }
        }

    }

6.结果显示