pwc
[Top] [All Lists]

[pwc] automatic gain control

To:
Subject: [pwc] automatic gain control
From: Roman Haefeli <>
Date: Thu, 13 Sep 2007 23:19:26 +0200
hello

i plan to use my SPC 900NC for an artistic project. therefor i want to
make a comparison between a buffered background image and the realtime
image in order to remove the background of the image.
however, this only works, if i manage to keep the gain stable. according
to 'setpwc -h', i am supposed to set a value for automatic gain control
by using "setpwc -g <0-65535>". actually, i am not quite sure what
"setting the automatic gain control" means. i mean, why is there a user
settings, when it is done automatically anyway?
i had the impression, that this setting doesn't affect anything or it
gets overwritten instantly by the automatic gain control. i found out,
that whenever i access the cam through setpwc (or mplayer or
whatsoever), the gain is adapted.

doing 'setpwc -p', while pointing the cam towards a light, i get:

Automatic gain control: -2502

doing the same while pointing the cam into the dark, i get:

Automatic gain control: -25815

to sum it up:
the option '-g' doesn't show any effect at all.
the values seem to be in the negative range, not in the range 0-65535,
as mentioned in the help.
is this a bug? (of pwc or setpwc?)
is there some way to get rid of automatic gain control?
is this something the driver does or the camera itself?

i am using:
pwc-10.0.12-rc1
setpwc v1.1

thanks in advance
roman





        
                
___________________________________________________________
Der frühe Vogel fängt den Wurm. Hier gelangen Sie zum neuen Yahoo! Mail: 
http://mail.yahoo.de
_______________________________________________
pwc mailing list

http://lists.saillard.org/mailman/listinfo/pwc
<Prev in Thread] Current Thread [Next in Thread>
Admin

Disclaimer: Neither Andrew Taylor nor the University of NSW School of Computer and Engineering take any responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU