clipboard - Webcam usage in C#

Question

I am making a program in C# to connect to a webcam and do some image manipulation with it. I have a working application that uses win32 api (avicap32.dll) to connect to the webcam and send messages to it that sends it to the clipboard. The problem is that, while accesible from paint, reading it from the program results in null pointers.

This is the code I use to connect the webcam:

mCapHwnd = capCreateCaptureWindowA("WebCap", 0, 0, 0, 320, 240, 1024, 0);

SendMessage(mCapHwnd, WM_CAP_CONNECT, 0, 0);
SendMessage(mCapHwnd, WM_CAP_SET_PREVIEW, 0, 0);

And this is what I use to copy the image to the clipboard:

SendMessage(mCapHwnd, WM_CAP_GET_FRAME, 0, 0);

SendMessage(mCapHwnd, WM_CAP_COPY, 0, 0);
tempObj = Clipboard.GetDataObject();
tempImg = (System.Drawing.Bitmap)tempObj.GetData(System.Windows.Forms.DataFormats.Bitmap);

Theres some error checking which I have removed from the code to make it shorter.

Thanks in advance :)

Answer 1

I've recently started doing some hobby work in this area.

We settled on using the OpenCV library with the opencvdotnet wrapper. It supports capturing frames from a webcam:

using (var cv = new OpenCVDotNet.CVCapture(0))
{
    var image = cv.CreateCompatibleImage();
    // ...
    cv.Release();
}

And if you're doing image manipulation, OpenCV's image processing algorithms have been wrapped within the OpenCVDotNet.Algs assembly.

If you decide to go this route be sure to install OpenCV version 1.0 (and install it to "c:program filesopencv" if you are on Vista 64-bit, or "mklink OpenCV 'c:program files (x86)OpenCV`" from the correct directory or else opencvdotnet will not install).