[ros-users] [Pr2-users] How to calibrate camera_synchronizer_node?

[Blaise Gassend]

Hi Ulrich,

I had a look at your bags, and I am noticing that there is a lot of
oscillation in the image intensity. Auto-gain/exposure don't work well
with alternating mode, and I would recommend switching them off.

> Thomas Rühr could help me out -i could not be in the lab today - and
> recorded two bags with a synchronization node including the code changes you
> proposed.

Thanks for the bags. I see in the textured an interval of 3 seconds
between flashes. Is that interval always the same, or is it different
each time?

Can you confirm that both cameras have problems at the same time?

>From the times at which the images are being sent, it looks like there
may be an extra or missing trigger pulse. I'm going to try to
reproduce this on one of our robots...

I wonder if you could send me a bag of the following topics:
/head_camera_trigger/waveform, /projector_trigger/waveform,
/head_camera_trigger/trigger_narrow_stereo_both,
/projector_trigger/on_time, /projector_trigger/off_time,
/narrow_stereo/left/camera_info,
/narrow_stereo_textured/left/camera_info,
/narrow_stereo/right/camera_info,
/narrow_stereo_textured/right/camera_info. You can make this one
pretty long, say a minute, as it is a lot less data.

> Do you think, that is solvable at all?

Hard to know until we know what the problem is.

> Can the projector be switched on and
> off instead of being modulated?

The projector cannot be turned on continuously because it would
overheat. It is limited to 2 ms pulses (I forget the exact duty
cycle). You can of course turn it off all the time, but I don't see
how that would help you if you need alternating mode.

One last thing: if you want to be able to filter out the images that
are having trouble, I believe that you can use the image timestamp.
The timestamps should be totally periodic when things are working
well. When you get the bad images, the interval between two images
will be different from what it usually is.

Cheers,
Blaise