c# opencvsharp学习笔记（7）均值偏移（meanshift）算法,Mat转位图，使用gdi+显示Mat

1.均值偏移

在6说过一般是使用HSV的色调通道就行所以，所以我们可以直接写成一个函数，输入源图和roi返回反向直方图

  static Mat HistBack(Mat src,Mat roi)
        {
               
            Mat srcHSV = new Mat();
            Mat roiHSV = new Mat();
            Cv2.CvtColor(src, srcHSV, ColorConversionCodes.BGR2HSV);//将图片转换成HSV空间
            Cv2.CvtColor(roi, roiHSV, ColorConversionCodes.BGR2HSV);//将图片转换成HSV空间
            int[] histsize = new int[] { 256 };//一个通道，初始化为256箱子
            Rangef[] range = new Rangef[1];//一个通道，范围
            range[0].Start = 0.0F;//从0开始（含）
            range[0].End = 180.0F;//到180结束（不含，色调的范围0到180
            int[] channels = new int[] { 0 };//一个通道,初始化为通道0,这些东西可以共用设置
           
            Mat[] rois  = Cv2.Split(roiHSV);//将roi拆分
            Mat[] rois0 = new Mat[] {rois[0] };//roi的第一个通道，也就是H，色调

            Mat mask = new Mat();//掩码;
            Cv2.Threshold(rois[1], mask, 65, 255, ThresholdTypes.BinaryInv);//过滤掉较低饱和度的像素

            Mat[] hist = new Mat[] { new Mat() };//一个矩阵数组，用来接收直方图,记得初始化
            Cv2.CalcHist(rois0, channels, mask, hist[0], 1, histsize, range);//把roi的色调通道转换成直方图

            Mat[] srcs = new Mat[] { srcHSV };
            Mat[] histBack = new Mat[] { new Mat() };//返回的反向直方图，一个通道就够
            Cv2.CalcBackProject(srcs, channels, hist[0], histBack[0], range);//输出反向直方图
            
            return histBack[0];
        }

 

            //试下
 Mat src = new Mat(@"1.png", ImreadModes.AnyColor);
 Rect rect = new Rect(520, 150, 80, 180);
 Mat roi = new Mat(src, rect);
 src.Rectangle(rect, Scalar.White);//在src上画框
 Mat dst = new Mat(@"2.png", ImreadModes.AnyColor);
 Cv2.MeanShift(HistBack(dst, roi), ref rect, new TermCriteria(CriteriaType.MaxIter, 10, 0.1));//框大小不会变化，其它一样
 //Cv2.CamShift(HistBack(dst, roi), ref rect, new TermCriteria(CriteriaType.MaxIter, 10, 0.1));//框大小会变化
 dst.Rectangle(rect, Scalar.White);//在dst上画框
 Cv2.ImShow("dst", dst);
 Cv2.ImShow("src", src);
 Cv2.WaitKey();

emmmm

 

2.Mat转位图并在pictureBox上显示

//需要 using OpenCvSharp.Extensions;

 

//pb5为winform的picturebox控件
       //点击picturebox显示
       Bitmap sion0;
       bool sioni = false;
   
        private void pB5_Paint(object sender, PaintEventArgs e)
        {
           Graphics g = e.Graphics; 
            if (sioni)
           {
                g.DrawImage(sion0, 0, 0);
           }
         
        }

        private void pB5_Click(object sender, EventArgs e)
        {
            Mat sion = new Mat("sion.png", ImreadModes.AnyColor);
            double time = Environment.TickCount;//系统启功后到当前的时间
            sion0 = sion.ToBitmap();//需要 using OpenCvSharp.Extensions;
            UM_print((Environment.TickCount-time).ToString());//在输出串口打印出消耗的时间
            sioni = true;
        }


        //直接显示
        static Mat sion = new Mat("sion.png", ImreadModes.AnyColor);
        static Bitmap sion0 = sion.ToBitmap();
        private void pB5_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            g.DrawImage(sion0, 0, 0);
        }

感谢@wyg2004  的提醒，已更新代码且满足性能需求，在当时困扰了好长一段时间。