Interfacing with a webcam

Question

So I am trying to develop a WPF app that will allow me to turn off the auto zoom and auto focus abilities of my webcam. I'm using the Emgu c# wrapper for opencv and want to be able to do frame differencing without my camera auto focusing when an object comes into the screen.

I have tried looking for an sdk that would allow me to develop something like this but apparently logitech ditched theirs a couple of years ago. I am using an HD pro Webcam c920. I have heard that maybe you can use the dll's that shipped with it to tweak the options but I have no idea how to do this.

Any help would be awesome.

Answer 1

Logitech HD Pro Webcam C920's Zoom, Exposure, Focus can be controlled using DirectShow API. Chances are high that Emgu CV is using DirectShow to capture (always, or as an option), or at least you possibly can set the camera up using DirectShow and the settings would survive restart of streaming sessions.

C920's properties are available using IAMCameraControl interface. It is documented on MSDN for native development, and DirectShow.NET offers respective definitions for .NET.