How to save IP camera snapshot in Content folder using EmguCV c# - camera

Question

I'm using EmguCV 3.4. I need to store snapshots from IP camera periodically(5 mins). I try to stored snapshots in the Content folder (ASP.NET MVC). I got access violation exception. Help me.
My Code,
private VideoCapture _capture = null;
private Mat _frame;
public void GetSnapshot(CameraDTO cameraDTO)
{
CvInvoke.UseOpenCL = false;
try
{
_capture = new VideoCapture(cameraDTO.CameraAccessURL);
_capture.ImageGrabbed += ProcessFrame;
if (StartCapture())
{
while (_frame == null)
{
//wait untill camera ready
}
if (_frame != null && _capture != null)
{
Image<Bgr, Byte> imgeOrigenal = _frame.ToImage<Bgr, Byte>();
imgeOrigenal.Save(#ImageSavepath + #"\ImageFromCamera" + cameraDTO.camID + ".jpg");
}
}
}
catch (Exception excpt)
{
Console.WriteLine(excpt.Message);
}
}
private bool StartCapture()
{
if (_capture != null)
{
_capture.Start();
return true;
}
return false;
}
private void ProcessFrame(object sender, EventArgs e)
{
try
{
if (_capture != null && _capture.IsOpened && _capture.Ptr != IntPtr.Zero && _frame != null)
{
_frame = new Mat();
_capture.Retrieve(_frame, 0);
}
}
catch (AccessViolationException exv)
{
Console.WriteLine("ERROR: {0}", exv.Message);
return;
}
catch (Exception ex)
{
Console.WriteLine("ERROR: {0}", ex.Message);
return;
}
}
#ImageSavepath = Content folder, randomly generate the issue

Answer 1

The problem is that you use _frame in another thread (cross-thread manipulating). You should save the image inside FrameProcess().
private void FrameProcess(object sender, EventArgs e)
{
try
{
if (_capture != null && _capture.IsOpened && _capture.Ptr != IntPtr.Zero && _frame != null)
{
_frame = new Mat();
_capture.Retrieve(_frame, 0);
Image<Bgr, Byte> imgeOrigenal = _frame.ToImage<Bgr, Byte>();
imgeOrigenal.Save(#ImageSavepath + #"\ImageFromCamera" + cameraDTO.camID + ".jpg");
}
}
catch (AccessViolationException exv)
{
Console.WriteLine("ERROR: {0}", exv.Message);
return;
}
catch (Exception ex)
{
Console.WriteLine("ERROR: {0}", ex.Message);
return;
}
}