unable to load cvextern in a c# project

Question

i'm trying to debug my program, using emgu and HaarCascade in c#. i'm getting an exception like so :

Unable to load DLL 'cvextern': The specified module could not be found. (Exception from HRESULT: 0x8007007E)

i've added the file cvextern.dll to my project and tried both "copy always" and "copy if newer" options on the properties of the file. also, the build is in platform x64.

here's partly what i wrote :

    private void Load_Click(object sender, EventArgs e)     {         OpenFileDialog dlg = new OpenFileDialog();         dlg.Filter = "Photo Files (*.jpg)|*.JPG";         dlg.CheckFileExists = true;         if (dlg.ShowDialog() == DialogResult.OK)         {             Image<Bgr, Byte> My_Image = new Image<Bgr, byte>(dlg.FileName);             HaarCascade face = new HaarCascade("haarcascade_frontalface_alt.xml"); 

and the exception is in the last line.

Answer 1

The error your receiving is not solely down to cvextern this dll actually points to almost all of the other opencv dlls and all are required. With this error you will require the following dll in your project.

Note that the "220" is the version number this will change according to updates.

• cudart64_32_16.dll
• cufft64_32_16.dll
• cvextern.dll
• npp64_32_16.dll
• opencv_calib3d220.dll
• opencv_contrib220.dll
• opencv_core220.dll
• opencv_features2d220.dll
• opencv_flann220.dll
• opencv_gpu220.dll
• opencv_highgui220.dll
• opencv_imgproc220.dll
• opencv_legacy220.dll
• opencv_ml220.dll
• opencv_objdetect220.dll
• opencv_video220.dll

This error is covered along with others in my article on codeproject here.

Any other problems let me know,

Cheers,

Chris

Answer 2

This error popped up on my side with Emgu CV 3.1 and I found for this issue a following working solution:

copy the cvextern.dll in the application directory \bin\Debug\

Hope this helps.