OpenCvSharp 识别颜色

安装

1. 新建winform程序
2. 安装OpenCvSharp包　

install-package OpenCvSharp4.Windows

开发

　　在 Form1窗体上添加一个按钮，在Click事件中添加如下代码：

   public partial class Form4 : Form
    {
        public Form4()
        {
            InitializeComponent();
        }
        private const string WINDOWS_NAME = "识别颜色";
 
        Mat img = new Mat();
        Mat mask = new Mat();
        Mat hsvMat = new Mat();

        private static int lowH = 98;
        private static int lowS = 193;
        private static int lowV = 0;
        private static int hightH = 150;
        private static int hightS = 255;
        private static int hightV = 255;

        private TrackbarCallbackNative callbackNative;
        private void button1_Click(object sender, EventArgs e)
        {

            //选择图片
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.RestoreDirectory = true;
            string imgName = "";
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                imgName = openFileDialog.FileName;
            } 
            img = Cv2.ImRead(imgName, ImreadModes.AnyColor);// new Mat("",);
            img.Resize(new OpenCvSharp.Size(500, 500));

            Cv2.CvtColor(img, hsvMat, ColorConversionCodes.BGR2HSV);

            onThresholdValueChange(1,img.Ptr());
            callbackNative = onThresholdValueChange;
            Cv2.CreateTrackbar("lowH", WINDOWS_NAME, ref lowH, 255, callbackNative, img.Ptr());
            Cv2.CreateTrackbar("lowS", WINDOWS_NAME, ref lowS, 255, callbackNative, img.Ptr());
            Cv2.CreateTrackbar("lowV", WINDOWS_NAME, ref lowV, 255, callbackNative, img.Ptr());
            Cv2.CreateTrackbar("hightH", WINDOWS_NAME, ref hightH, 255, callbackNative, img.Ptr());
            Cv2.CreateTrackbar("hightS", WINDOWS_NAME, ref hightS, 255, callbackNative, img.Ptr());
            Cv2.CreateTrackbar("hightV", WINDOWS_NAME, ref hightV, 255, callbackNative, img.Ptr());
        }
        
        private  void onThresholdValueChange(int pos, IntPtr userData)
        {
            var lowPurple = new Scalar(lowH, lowS, lowV);
            var highPurple = new Scalar(hightH, hightS, hightV);
            Cv2.InRange(hsvMat, lowPurple, highPurple, mask);
            var kernel = Cv2.GetStructuringElement(MorphShapes.Rect, new OpenCvSharp.Size(20, 20),
                new OpenCvSharp.Point(-1, -1));
            Cv2.Threshold(mask, mask, 0, 255, ThresholdTypes.Binary); //二值化
            Cv2.Dilate(mask, mask, kernel); //膨胀
            Cv2.Erode(mask, mask, kernel);//腐蚀
            OpenCvSharp.Point[][] contours;
            HierarchyIndex[] hierarchy;
            Cv2.FindContours(mask, out contours, out hierarchy, RetrievalModes.CComp, ContourApproximationModes.ApproxSimple, null);
            if (contours.Length > 0)
            {
                var boxes = contours.Select(Cv2.BoundingRect).Where(w=>w.Height>=10 && w.Width>10);
                var imgTar = img.Clone();
                foreach (var rect in boxes)
                {
                    Cv2.Rectangle(imgTar, new OpenCvSharp.Point(rect.X, rect.Y), new OpenCvSharp.Point(rect.X + rect.Width, rect.Y + rect.Height), new OpenCvSharp.Scalar(153, 153, 0), 2);
                }
                Cv2.ImShow(WINDOWS_NAME, imgTar);
            }
            else
            {
                Cv2.ImShow(WINDOWS_NAME, img);
            }
        }
    }

效果如下：

   可以把托盘中没有瓶子的 位置都给识别出来

腐蚀