title: Webcam picture too dark link: https://onemoretech.wordpress.com/2009/07/01/webcam-picture-too-dark/ author: lembobro description: post_id: 290 created: 2009/07/01 21:53:30 created_gmt: 2009/07/01 21:53:30 comment_status: open post_name: webcam-picture-too-dark status: publish post_type: post

Webcam picture too dark

So this is a problem I had with Skype. Most Linux apps that use a webcam actually provide a way to adjust brightness and contrast. Not Skype. Probably because this requires root privileges, and they know no self-respecting Linux admin is going to give them that.

The fix is actually pretty easy.

First, to see immediate results do this:

echo 4 /sys/module/gspca/parameters/gamma echo 290 /sys/module/gspca/parameters/GRed echo 310 /sys/module/gspca/parameters/GGreen echo 315 /sys/module/gspca/parameters/GBlue

Don’t assume that these parameters are infinitely hackable. For example, I found a gamma of 6 had no effect but that 4 brightened things right up.

If these settings work for you, put them into /etc/modprobe.d/options (if it doesn’t exist yet, create it) so they’ll come back after your next reboot. Thus:

options gspca gamma=4 options gspca GRed=290 options gspca GGreen=310 options gspca GBlue=315

Thanks to user Excalibur on Skype Community for this tip.

Copyright 2004-2019 Phil Lembo