void _grabber_OnFrame(Parsley.Core.BuildingBlocks.FrameGrabber fg, Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte> img) {
// Note: This method is called from the frame-grabber's thread loop.
// The framegrabber holds a Breath on the camera to ensure that the camera object remains
// alive during this callback. The camera object is a SharedResource, meaning that any
// invocation to Dispose will block until all Breaths on the camera are released. Suppose
// The thread that owns the picture box has called dispose and blocks. The callback here is called
// and invoke is used. Invoke executes the delegate on thread that owns this control, which is the one
// that is already blocked. This leads to a deadlock. That is why we use BeginInvoke, which executes
// the delegate on the GUI thread associated with this control.
if (_can_invoke) {
Rectangle client = this.ClientRectangle;
Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte> img_copy = img.Resize(client.Width, client.Height, _interpolation);
this.BeginInvoke(new MethodInvoker(delegate {
// Update image
Emgu.CV.IImage prev = _picture_box.Image;
_picture_box.Image = img_copy;
if (prev != null) {
prev.Dispose();
}
}));
}
}