How to get video stream from webcam in emgu cv?

问题:

I'm using emgu cv in c#.

I need to know How I can get the video stream from my webcam(default webcam)in emgu cv?

回答1:

You can use the following code to make an app to capture and display video stream:

public class CameraCapture
{
    private Capture capture;  //takes images from camera as image frames
    private bool captureInProgress;

    private void ProcessFrame(object sender, EventArgs arg)
    {
        Image<Bgr, Byte> ImageFrame = capture.QueryFrame();  //line 1
        CamImageBox.Image = ImageFrame;  //line 2
    }
    private void Form1_Load(object sender, EventArgs e)
    {
        if (capture == null)
        {
            try
            {
                capture = new Capture();
            }
            catch (NullReferenceException excpt)
            {
                MessageBox.Show(excpt.Message);
            }
        }

        if (capture != null)
        {
            if (captureInProgress)
            {  //if camera is getting frames then stop the capture and set button Text
                // "Start" for resuming capture
                btnStart.Text = "Start!"; //
                Application.Idle -= ProcessFrame;
            }
            else
            {
                //if camera is NOT getting frames then start the capture and set button
                // Text to "Stop" for pausing capture
                btnStart.Text = "Stop";
                Application.Idle += ProcessFrame;
            }
            captureInProgress = !captureInProgress;
        }
    }
}

回答2:

Not sure what you want to do with the data, but this will get you a single frame from the camera (and display it in a pictureBox on a WinForm)

private void Form1_Load(object sender, EventArgs e)
{            

    var capture = new Emgu.CV.Capture();

    using (var nextFrame = capture.QueryFrame())
    {
        if (nextFrame != null)
        {                           
            pictureBox1.Image = nextFrame.ToBitmap();
        }
    }                         
}