Re: 2D_PTV_Calibration initial guess problem

[Alex Liberzon]

it would be simpler if you share the folder with the calibration and parameters 

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From: ope...@googlegroups.com <ope...@googlegroups.com> on behalf of Zitao Jiang <china...@gmail.com>
Sent: Saturday, December 31, 2022 12:14:33 PM
To: openptv <ope...@googlegroups.com>
Subject: 2D_PTV_Calibration initial guess problem

 

Dear group

I am testing a 2D-PTV case, and I have some problems with calibration.

When I click initial guess, the yellow dots are overlapping and they do not match the target points.

How can I fix this probelm?

Best Regards

Jiang

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[Alex Liberzon]

replace 3.14 angle with 0 

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From: Alex Liberzon <alex.l...@gmail.com>
Sent: Saturday, December 31, 2022 12:51:42 PM
To: Zitao Jiang <china...@gmail.com>; openptv <ope...@googlegroups.com>
Subject: Re: 2D_PTV_Calibration initial guess problem

 

[Zitao Jiang]

Hello, Alex,

I change anle to 0, it still shows the same initial guess.

I attahced the file here.

[Alex Liberzon]

there was a problem in cam_1.tif.addpar - not sure how you could arrive at that file if not manually.

[Zitao Jiang]

Hi Alex,

Thank you for your help, it can be calibrated correctly now.

I have a new problem with tracking.

After clicking the tracking without display, the commands says multimed_r_nlay stopped after 40 iterations and it seems that it does not link the particle between frames.

Do you have any idea what is the possible reason for this？

I have two other basic questions:

1. where do we define the frame per second we used in experiment (the time difference between two frames)?

2. what is the unit of tracking parameters? I think it defines the maximum search windows for the same particle between two frames. Is the unit mm? 

Thank you for your time to check my problems.

Best Regards

Jiang

[Zitao Jiang]

Hi, Alex

I changed refractive indices of air glass and water to 1.

But when I did tracking process, there is no link and all the particles are lost.

Is it because of improper tracking parameters?

[Alex Liberzon]

most probably. 

 

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