CannyWebcam.cs

// CannyWebcam.cs
//
// Emgu CV 3.0.0
//
// put this code in your main form, for example frmMain.cs
// add the following components to your form:
//
// tableLayoutPanel (TableLayoutPanel)
// ibOriginal (Emgu ImageBox)
// ibCanny (Emgu ImageBox)
//
// NOTE: Do NOT copy/paste the entire text of this file into Visual Studio !! It will not work if you do !!
// Follow the video on my YouTube channel to create the project and have Visual Studio write part of the code for you,
// then copy/pase the remaining text as needed

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using Emgu.CV;                  //
using Emgu.CV.CvEnum;           // usual Emgu CV imports
using Emgu.CV.Structure;        //
using Emgu.CV.UI;               //

///////////////////////////////////////////////////////////////////////////////////////////////////
namespace CannyWebcam1 {

    ///////////////////////////////////////////////////////////////////////////////////////////////
    public partial class frmMain : Form {

        // member variables ///////////////////////////////////////////////////////////////////////
        Capture capWebcam;

        // constructor ////////////////////////////////////////////////////////////////////////////
        public frmMain() {
            InitializeComponent();
        }

        ///////////////////////////////////////////////////////////////////////////////////////////
        private void frmMain_Load(object sender, EventArgs e) {
            try {
                capWebcam = new Capture(0);
            } catch(Exception ex) {
                MessageBox.Show("unable to read from webcam, error: " + Environment.NewLine + Environment.NewLine +
                                ex.Message + Environment.NewLine + Environment.NewLine +
                                "exiting program");
                Environment.Exit(0);
                return;
            }
            Application.Idle += processFrameAndUpdateGUI;       // add process image function to the application's list of tasks
        }

        ///////////////////////////////////////////////////////////////////////////////////////////
        void processFrameAndUpdateGUI(object sender, EventArgs arg) {
            Mat imgOriginal;

            imgOriginal = capWebcam.QueryFrame();

            if(imgOriginal == null) {
                MessageBox.Show("unable to read frame from webcam" + Environment.NewLine + Environment.NewLine +
                                "exiting program");
                Environment.Exit(0);
                return;
            }

            Mat imgGrayscale = new Mat(imgOriginal.Size, DepthType.Cv8U, 1);
            Mat imgBlurred = new Mat(imgOriginal.Size, DepthType.Cv8U, 1);
            Mat imgCanny = new Mat(imgOriginal.Size, DepthType.Cv8U, 1);

            CvInvoke.CvtColor(imgOriginal, imgGrayscale, ColorConversion.Bgr2Gray);

            CvInvoke.GaussianBlur(imgGrayscale, imgBlurred, new Size(5, 5), 1.5);

            CvInvoke.Canny(imgBlurred, imgCanny, 100, 200);

            ibOriginal.Image = imgOriginal;
            ibCanny.Image = imgCanny;
        }
        
    }   // end class

}   // end namespace