CODEWITHSUNDEEP
c#opencvemgucv
Luiz de Prá
Luiz de Prá

Reputation: 1475

How can I get a EmguCV ImageBox image?

I'm trying to select a pixel color of the frames of my webcam. So I capture the frames an show then in a ImageBox without any problem. But when I try to access the image stored on ImageBox when I double click on the ImageBox I get a CvException. The exception pop when I try to get the pixel of the image.

OpenCV: unrecognized or unsupported array type

This is how I capture the frames:

// On Form Load
Application.Idle += ProcessFrame;

private void ProcessFrame(object sender, EventArgs arg)
    {
        if (cap != null)
        {
            using (Image<Bgr, byte> frame = cap.QueryFrame())
            {
                if (frame != null)
                {
                    imageFrame = frame;
                    imageBoxFrame.Image = imageFrame;

                    Bgr color = imageFrame[50, 100];
                }
            }
        }
    }

And in DoubleClick Event:

private void imageBoxFrame_MouseDoubleClick(object sender, MouseEventArgs e)
    {
        if (treeViewObjects.SelectedNode is ColorNode && !isTracking)
        {
            if (imageFrame == null)
                return;

            Emgu.CV.UI.ImageBox imageBox = (Emgu.CV.UI.ImageBox)sender;
            Image<Bgr, byte> image = (Image<Bgr, byte>)imageBox.Image;

            Bgr color = image[e.X, e.Y]; // This line causes the Exception
        }
    }

Apparently the image is not null. What I doing wrong? Maybe something with thread things?

Upvotes: 2

Views: 7554

Answers (1)

Brian Tompsett - 汤莱恩
Brian Tompsett - 汤莱恩

Reputation: 5893

(Question answered by the OP and Answer posting requested. See Question with no answers, but issue solved in the comments (or extended in chat) )

The OP wrote:

I solved it.

I just need to Clone the image because the using statement erase image data. So, on ProcessEvent I just need to clone the frame to imageFrame.

imageFrame = frame.Clone();

And have another problem. The correct way to access the pixel data is by [Y,X] not [X,Y].

Bgr color = image[e.Y, e.X];

Upvotes: 3

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