The QuickCam CCD suffers from "dark current"; that is, some of the CCD
pixels will leak current under long exposures, even if they're in the
dark, and this shows up as ugly speckling on images taken in low
Fortunately, the leaky pixels are the same from shot to shot. So, we
can figure out which pixels are leaky by taking some establishing
shots in the dark, and try to fix those pixels on subsequent shots.
The dark establishing shots need only be done once per camera.
This is what
does. This program, which must be run when the QuickCam is in
darkness, figures out which pixels are leaky, and writes a mask to
which lists those pixels.
/etc/qcam.darkfile Dark mask file
You can have multiple Cams and multiple config files, but only one dark
The new Color QuickCam is not handled with this software, although
there are Color Cam drivers available from the web site.
Scott Laird (original code), Brian Scearce (bidirectional
and dark current modifications,
window scaling, edge detection), Ed Orcutt (autoexposure modifications),
Dave Plonka (locking code). This manpage written by Ben Pfaff
<firstname.lastname@example.org> for the Debian GNU/Linux qcam package, using
information from make.darkmask.c.