Emgu.CV.CvInvoke' threw an exception

Question

I am trying to use EMGUCV for C#. Currently i have installed Visual Studio 2010 express Edition. When trying to execute some simple commands the Emgu.CV.CvInvoke threw an exception came out so i put the unmanaged code in the exe folder. But still it continued to give me the error. So i tried adding the unmanaged code to solution explorer and still it is giving me this error. Is there anything else which i can do so i can finally use emguCV?

The exception is

System.TypeInitializationException was unhandled 
   Message=The type initializer for 'Emgu.CV.CvInvoke' threw an exception.

having stack trace:

   at Emgu.CV.CvInvoke.cvCreateCameraCapture(Int32 index)
   at Emgu.CV.Capture..ctor(Int32 camIndex) in C:\Program Files (x86)\Emgu\libemgucv-windows-x64-2.2.1.1150\Emgu.CV\Capture\Capture.cs:line 105
   at Emgu.CV.Capture..ctor() in C:\Program Files (x86)\Emgu\libemgucv-windows-x64-2.2.1.1150\Emgu.CV\Capture\Capture.cs:line 93
   at cameraWorks.Form1.camButton_Click(Object sender, EventArgs e) in C:\Users\Adrian\documents\visual studio 2010\Projects\cameraWorks\cameraWorks\Form1.cs:line 38
   at System.Windows.Forms.Control.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnClick(EventArgs e)
   at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ButtonBase.WndProc(Message& m)
   at System.Windows.Forms.Button.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)
   at cameraWorks.Program.Main() in C:\Users\Adrian\documents\visual studio 2010\Projects\cameraWorks\cameraWorks\Program.cs:line 18
   at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
   at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

InnerException:

InnerException: System.BadImageFormatException Message=An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B) Source=Emgu.CV StackTrace: at Emgu.CV.CvInvoke.cvRedirectError(CvErrorCallback errorHandler, IntPtr userdata, IntPtr prevUserdata) at Emgu.CV.CvInvoke..cctor() in C:\Program Files (x86)\Emgu\libemgucv-windows-x64-2.2.1.1150\Emgu.CV\PInvoke\CvInvoke.cs:line 50

I am only executing some simple code being:

public partial class Form1 : Form
{
    private Capture capture;
    private bool captureInProgress;

    public Form1()
    {
        InitializeComponent();
    }

    private void ProcessFrame(Object sender, EventArgs args )
    {
        Image<Bgr, Byte> ImageFrame = capture.QueryFrame();
        CamImageBox1.Image = ImageFrame;
    }

    private void camButton_Click(object sender, EventArgs e)
    {
        if (capture == null)
        {
            try
            {
                capture = new Capture();
            }
            catch (NullReferenceException excpt)
            {
                MessageBox.Show(excpt.Message);
            }
        }

        if (capture != null)
        {
            if (captureInProgress)
            {
                camButton.Text = "start";
            }
            else
            {
                camButton.Text = "stop";
                Application.Idle += ProcessFrame;
            }
            captureInProgress = !captureInProgress;
        }
    }

    private void ReleaseData()
    {
        if (capture != null)
        {
            capture.Dispose();
        }
    }

The examples of emguCV work on my computer. Thanks Alot Adrian

Answer 1

The following error: "An attempt was made to load a program with an incorrect format." is shown if the unmanaged assembly is compiled for different platform than your .NET code is currently executing on.

For example: take some dll that is compiled for x86, import some function call to C# and run. If you have 64-bit Windows this will fail, because .NET code is compiled to x64.

To overcome this you have two possibilities: 1) to use unmanaged dll version that matches your platform 2) Project -> Properties -> Build -> tick the platform that matches the platform for which an unmanaged dll is compiled (x86, x64) (it is probably set to Any CPU).

---

Copy your unmanaged dlls into \bin\Debug and/or \bin\Release project, not into some subfolder!! If you really want to use dlls from some subfolder, than edit the process environment variable like this:

Environment.SetEnvironmentVariable(path, Environment.GetEnvironmentVariable(path) + Path.PathSeparator + );

this will add your subfolder into search path. This variable is process variable meaning that all changes will be undone when process stops executing.