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"Inverted" Tracking question

Posted: Mon Dec 19, 2011 3:11 am
by Matan
Hello,
I would like to get some suggestions for approaching my project.

In my project I need to track 2D position of an ant.
The straightforward solution was to attach the little insect with a marker, but this is not applicable :(

I thought about working "inverted": Place the ant on a large reflective paper, 2 X 2 m, and try to track the pixels where there is no reflection.
If I will use this approach, how technically should I use the SDK? Use rasterize? Use a short expose so camera won't be dazed. What else should I do?

Other approach was to place a large sheet (2X2) with a lot of tiny markers which are very close. Marker size will be 2 millimeter and the space between markers will be also 2 millimeter. While the ant will move I can track by calculating the markers which disappeared. This approach is also problematic, using e250 camera I still didn't have enough resolution, all the small markers seemed to be a single large marker! :( What should I do, in order to identify clearly all small markers?
Any other Idea? Approach?

Thanks
Mat

Re: "Inverted" Tracking question

Posted: Mon Dec 19, 2011 6:21 pm
by NaturalPoint - Mike
I'd really like to be able to answer this. What size ant? Would it be possible to test putting the ant on a marker and putting the marker at the expected distance from the camera to test?

This would suggest it's doable (I did not get the entire article, however the abstraction hinted that it was the same method). Whether this is practical at 2m with an s250e may depend entirely on the size of the ant.

Re: "Inverted" Tracking question

Posted: Wed Dec 21, 2011 8:14 am
by Matan
Thanks for the quick reply

Yes, I already tested it, and the results are as mentioned:
The camera didn't notice the un-marked \ shaded (by the ant) erea, the camera was "dazed" from all background marker

The insect size is something like 5 millimeter radius.
Maybe there is away to configure e250 camera so it won't be dazed and resolution will be better, so I can notice the small unmarked object?

Thanks
Mat

Re: "Inverted" Tracking question

Posted: Fri Dec 23, 2011 2:06 pm
by NaturalPoint - Mike
Can it see the ant in MJPEG mode?

Perhaps a shorter exposure period with low power continuous IR would help.

Re: "Inverted" Tracking question

Posted: Mon Dec 26, 2011 3:48 am
by Matan
Not possible to view in MJPEG

I tried short exposure.
What is low power IR at SDK ? Intensity?

Re: "Inverted" Tracking question

Posted: Wed Dec 28, 2011 11:19 am
by NaturalPoint - Mike
Correct.

First things first, I would recommend making sure you have the latest version of the Camera SDK, as continuous mode for S250e cameras is a more recent addition. Then you can use the following:

bool CameraLibrary::Camera.IsContinuousIRAvailable(); to query if continuous mode is allowed on your camera.

void CameraLibrary::Camera.SetContinuousIR(bool Enable); to switch between strobed and continuous (true = continuous)

void CameraLibrary::Camera.SetIntensity(int Value); to set the intensity between 0 (off) and 15 (full).

Continuous IR will output less light with the same intensity value compared to strobed, so the lowest amount of output light you can hope to achieve is:
mode = continuous
intensity = 1