Motion - Bug Report 2005x 08x 15x 160208

BUG: Autobrightness is unstable

I'm trying to uso motion outdoor with a Creative NX Ultra webcam. I've activated autobrightness but the image can't reach a stable state and oscillates between very dark and white. I tested also with a Quickcam Express there's the same problem.

Test case

Environment

Motion version: 3.2.2
ffmpeg version:  
Shared libraries:  
Server OS: FC 2, 2.6.12.1

-- TWikiGuest - 15 Aug 2005

Follow up

Fix record

I think I have fixed it. At least for some. The fix is in release 3.2.3 (16 Aug 2005).

Did you run with pre_capture > 0 or minimum_motion_frames > 1? If so then one bug is now fixed.

If your camera already adjusts brightness then it may not work anyway.

-- KennethLavrsen - 16 Aug 2005


> Did you run with pre_capture > 0 or minimum_motion_frames > 1? If so then one bug is now fixed.

No, pre_capture = 0 , minimum_motion_frames = 1 I've tried also version 3.2.3 but there are oscillations.

> If your camera already adjusts brightness then it may not work anyway.
It hasn't autobrightness

I played with camera brightness control and I noticed it has a very non-linear response. (Eg. from 20000 to 26300 there's little change, from 26300 to 26400 the image changes a lot). This may be the reason.

-- TWikiGuest - 17 Aug 2005

Yes. If the camera does not have a linear or close to linear response then it is close to impossible to make a regulation loop that works in practical without making a unique one for this one type camera which would be a bit of an overkill. If I make the steps too small I risk that some camera to not regulate at all.

-- KennethLavrsen - 17 Aug 2005
Topic revision: r4 - 17 Aug 2005, KennethLavrsen
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