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Stereo vision calibration failed

Hi guys,

I'm using the Calibrate stereo vision.vi (NI Vision development module 2013) to calibrate my stereo vision system but I failed and I don't know why. My experimental setup is as follows:

2 aviator 1600gc cameras, with 16mm focal lenses and a baseline of 1 cm;

a calibration grid of 16*16 dots (dx=dy=4 cm), at a distance of 2 meters;

2 light projector of 500 W.

 

I followed the VI instructions and made a lot of trials for 2 days, but i never succedeed in calibration. More specific, in the grid coverage control i always obtain NaN %, as showed in the picture in the attachment.

In continued to acquire images as long as all gride coverage control below are all to 100% but the VI doesn't proceed into grid vertex calibration.

 

Can someone help me?

Thanks in advanceProblema_calibrazione.png

 

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Message 1 of 6
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Hi Carlofeo,

 

I think the problem is that the calibration grid is too far from the cameras and the system doesn't detect the dots inside the grid.

I suggest you to obtain something like this to correctly calibrate your system: http://zone.ni.com/reference/en-XX/help/370281W-01/imaqvision/stereo_vision_example/

 

Hope it helps,

have a nice day!

 

FBM

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Hi there,

 

I got exactly the same problem! I hope it's okay posting in this topic.

I followed the instructions on http://zone.ni.com/reference/en-XX/help/370281U-01/imaqvision/stereo_vision_example/ but my top grid coverage just won't show any values.

The grid is from the NI folder, so actually it should  be okay.

 

cams: 2x DMK 23F618 from ImagingSource

lenses: 2x 8mm F1.2

 

calibration.PNG

Furthermore, at most attempts I won't even get any values at all.

 

calibration1.PNG

Even if all points are detected it won't show any values. This mostly happens when I use external light sources (tried it with infrared and a common 20W halogen lamp running on DC)

 

 

I hope you can help me out here! Thanks

 

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As I don't know how to edit my previous post, I'd just make a new one..

 

I found out that i kinda get some values when I turn on the Highlight Funktion in the Calibration-Manager.vi.

Means there is a timing problem, most certainly in this sub-vi! I'm not sure how to solve it yet though..

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I manged to solve it:

 

Searching for the timing problem, it led me to the Calibration Manager (Init Case):

reprogramming the case as following solved the issue:

calib.JPG

Message 5 of 6
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Hi Maxtur;

First of all, I want to thank you for your help. I have solved the problem in the Calibration Manager (Init Case) by programming the case as you mentioned. But now, I couldn't calibrate the stereo imaging system and pass to the next step (measurement). I have usually same problem at the grid covarage section. I set up a test bench for calibration and measurement. I have worked all day but I did not get a result.

Thanks for your kind interest,

Dr. Baris Ozluoymak

 

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