webcam capture brightness (dark image)

[Marko Petejan]

Bus 001 Device 002: ID 04f2:b008 Chicony Electronics Co., Ltd USB 2.0 Camera
(notebook Toshiba Qosmio X300 integrated webcam)

In less than optimal light conditions image from webcam tends to become too dark, sometimes almost black. Not in obvious way.
The darker the ambient, more chances are, the image will become dark. This has nothing to do with poor lighting conditions. Sometimes it's OK for half a minute and then in a second or two it becomes dark, sometimes its dark from the start (after a second or two) and sometimes its nice and bright all the time.
This is happening at exactly the same ambient light conditions and all three conditions can be sometimes observed after few consecutive restarts of a video application.
FPS rate is 28. It seems that some autoexposure setting gets autoscrewed (misscalculation affected by elevated noise presence?) or perhaps some noise removal algorithm gets too effective.
Changing settings like brightness, gamma, etc. has no effect, as it seems it changes the resulting dark picture not the exposure time.
The problem is persistent in all tested webcam capable applications (cheese, ekiga, luvcview, vlc, skype,...) and its seen (tested) since Ubuntu 9.04.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: libv4l-0 0.6.4-1ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-22.33-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-22-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Mon May 31 10:21:25 2010
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
ProcEnviron:
 LANG=sl_SI.utf8
 SHELL=/bin/bash
SourcePackage: libv4l

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.