Re: [Spca50x-devs] spca561a Exposure controll (Solution: software autoexposure)
- Date: Sat, 7 Oct 2006 13:09:51 +0200
- From: Hakan Ardo <hakan@xxxxxxxxxx>
- Subject: Re: [Spca50x-devs] spca561a Exposure controll (Solution: software autoexposure)
Hi,
it turns out that the exposure time can be controlled by the contrast v4l
setting. I've now written a regulator controlling the contrast and
brightness v4l settings trying to get the mean gray level to 128 and it's
standard deviation to 74 (std of uniform distribution between 0 and 255).
It works fairly well, but has to calculate the mean and std over the image.
I beleve there is hardware support in the camera for calculating these
statistics. Does anyone know how to access them?
If you're interested in the regulator-code I'll be happie to publish it,
just let me know...
On Sun, Oct 01, 2006 at 08:45:58AM +0200, Hakan Ardo wrote:
> Hi,
> I have two different Logithech QuickCam Express cameras, with id
> 046d:0928 and 046d:092f, which I am accessing using gspcav1. Both
> cameras gives me overexposed images. In normal lighting the entire
> image is white. In dark environments I can get some very noisy images.
> I have tried both gspcav1-20060925 and gspca-20060831/gspcav1 with the
> same results using spcaview. Any ideas?
>
> Thanx
>
>
> --
> Hakan Ardo
--
Hakan Ardo
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