[Elphel-support] low framerate in stereo setup

[Andrey Filippov]

Jorick,

there is no way to scale resolution "a bit" with any Bayer mosaic sensors
and the ones used  in Elphel cameras is no exception.  Yes, most sensors
have decimation mode, but that is mostly for viewfinder application (related
binning is useful in low light conditions during night time when you need to
switch in the same sensor high res/low sensitivity- low res/high
sensitivity), because resolution drops more that proportional to number of
pixels (and so the frame rate). Perfect decimation is only possible in the
monochrome sensors See for yourself:

In the full-res mode you get:

G R G R G R G R
B G B G B G B G
G R G R G R G R
B G B G B G B G
G R G R G R G R
B G B G B G B G
G R G R G R G R
B G B G B G B G

in decimated by 2 in each direction (most popular) - "x" - skipped pixel:

G R x x G R x x
B G x x B G x x
x x x x x x x x
x x x x x x x x
 G R x x G R x x
B G x x B G x x
x x x x x x x x
x x x x x x x x

There are 2-pixel gaps, not 1 pixels ones as in monochrome senors"

Y Y Y Y
Y Y Y Y
Y Y Y Y
Y Y Y Y

Y x Y x
x x x x
Y x Y x
x x x x

If you still want to use decimation in your application - the sensor and
Elphel camera support various decimation (and binning) modes. You can
control these modes from php, parmeter editor or from camera GUI (camvc).

Andrey



On Mon, Aug 16, 2010 at 7:24 AM, Jorick Astrego <jorick at netbulae.com> wrote:

>  Dear all,
>
> Currently we have the stereo setup running and it's looking very nice.
>
> Is there a way to scale the resolution back a bit? Currently it's
> running on maximum resolution with the corresponding low framerate. We
> would not mind reducing the resolution a bit if it will improve the
> framerate but when I do that using the camera control interface I get
> garbage output.
>
> Any other way of impoving the framerate or are we running against a
> hardware limit?
>
> --
> Regards,
>
> Jorick Astrego
> Technisch Directeur
>
> Netbulae B.V.
> Site: http://www.netbulae.com
>
>
>
>
> _______________________________________________
> Support-list mailing list
> Support-list at support.elphel.com
> http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com
>
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