Raspberry Pi OpenCV With Lifecam HD-3000

[snekiam]

Has anyone been able to change camera parameters programmatically (such as exposure or buffer size) using the Microsoft LifeCam HD-3000? When we attempt to do this, we get an "error property not supported by device". Yet I am able to change some of these parameters from the command line. Anyone have any ideas?

[dcarr]

What are you using to change the parameters from the command line? Are you able to successfully capture images with a tool like v4l2-ctl with those settings?

[snekiam]

What are you using to change the parameters from the command line? Are you able to successfully capture images with a tool like v4l2-ctl with those settings?
We are using V4L2-ctl to change settings from the command line. I don't know how to capture an image with v4l2-ctl

[BenBernard]

I have been unable to set the exposure via OpenCV calls on the pi, although the same code running in Windows or MacOSX works fine.

However, I AM able to set the exposure using v4l2-ctl:

$ v4l2-ctl --set-ctrl=exposure_auto=1
$ v4l2-ctl --set-ctrl=exposure_absolute=25

Running this before launching our OpenCV-based code seems to do the trick.

YMMV

[jreneew2]

Do these changes stick through restart? I'm looking for a solution as well because even when I change the setting on the lifecam through my pc, the changes are different when I put it into the roboRIO. Also, does v4l2-ctl come pre-installed on the RIO or did you install it yourself?

[BenBernard]

My post was regarding raspberry pi, not the roborio--I'm not sure if v4l2-ctl is pre-installed on the roborio.

The changes do not "stick" but we've added them to the shell script that starts our vision tracking app.