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From: Michael Riepe <michael.riepe@googlemail.com>
To: aldoric@gmx.de
Cc: linux-media@vger.kernel.org
Subject: Re: [Question] USB-Web-Cam becomes slower as darker the image becomes
Date: Tue, 14 Jul 2009 18:32:21 +0200	[thread overview]
Message-ID: <4A5CB315.5050300@googlemail.com> (raw)
In-Reply-To: <20090714161428.49520@gmx.net>

Hi!

aldoric@gmx.de wrote:
> Hello,
> 
> I'm new to v4l-development. I was able to get the raw image into my application successfully. But the current problem is not only in limited to my self-developed application.
> 
> All of my USB-webcams will get less FPS as darker the image becomes. In optimal cases I get around 30 frames per second. But if it's really dark I only get around 2-3 FPS.

I suppose the camera (or the driver) is increasing the exposure time to
compensate for the lack of light and/or reduce noise.

> I think that it might be the software gamma-correction. On v4l2ucp I didn't find a way to disable it.

I don't think that will help. But you may try to turn off auto-exposure.

-- 
Michael "Tired" Riepe <michael.riepe@googlemail.com>
X-Tired: Each morning I get up I die a little

      reply	other threads:[~2009-07-14 16:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-14 16:14 [Question] USB-Web-Cam becomes slower as darker the image becomes aldoric
2009-07-14 16:32 ` Michael Riepe [this message]

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