How to disable automatic white balance from Webcam?

I got a webcam and I'm running some algorithm on the开发者_开发百科 received images to find movements in it. But, the automatic auto white balance is changing the excepted result of the pixels color variance. That's why I'm trying to disable it. Some one knows a way to get the web can image with out this automatic color balance or disable it ?

Tks

If you are on Linux, you can test disabling automatic white balance using the uvcdynctrl command line utility. This is not a permanent solution, since these settings are reset every time the webcam is disconnected from the computer. As of OpenCV 2.1, configuring white balance is not supported using cv::VideoCapture::set(). Assuming this is still the case in OpenCV 2.2, you will need to use another library to configure your webcam and capture frames.

If you on Linux, you can see an example of using direct Video4Linux (V4L) syscalls to do this in one of my Github projects.

In my case I found on driver two options that must be disabled, auto white exposure and auto white balance, I disable both of them and the image got as I needed.