How to apply mask before tracking paticles

[Chris Xu]

Dear community,

I want to apply a mask before tracking particles in openptv so it won't track particles in the grain areas but I am not sure how to do that. I saw the subtract mask option under "Main Parameters" but it asks for the base name for the mask (as shown below):

Anyone can help me with how to use the subtract mask feature? I have attached the mask that needs to be applied below as well (the white areas are grain and the particles can only pass through the black areas).

Thanks in advance,

Chris

[Alex Liberzon]

please upload also the working folder with some images. especially if you use a multi-camera system we need to think how to implement 2-4 masks to 2-4 cameras 

i think at the moment the mask is not fully implemented, but it is not too long to complete 

Best regards

Alex 

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From: ope...@googlegroups.com <ope...@googlegroups.com> on behalf of Chris Xu <chris...@gmail.com>
Sent: Friday, February 17, 2023 11:56:02 AM
To: openptv <ope...@googlegroups.com>
Subject: How to apply mask before tracking paticles

 

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[Alex Liberzon]

meanwhile, I recommend using scikit-image outside of pyptv to create masked images

[Alex Liberzon]

Please update your pyptv version to 0.1.9

`pip install pyptv --upgrade`

or from git:

`pip install git+https://github.com/alexlib/pyptv --upgrade`

How to use masking: 

1. in the Main parameters GUI check the box `Subtract Mask`

2. add the base name in the form `mask_#.tif` or `img/<your_filename>_#.tif` where `#` is the camera number

3. store in the working folder the file per camera, i.e., mask_1.tif, mask_2.tif ... and so on

In the parameters, folder should appear JSON file - but only in the corresponding Run

An example of the working folder with the masking.json is on GitHub https://github.com/alexlib/openptv_test_case_fall2023  and you can try:

`git clone https://github.com/alexlib/openptv_test_case_fall2023 .`

`python pyptv/pyptv_gui.py openpiv_test_case_fall2023`

Good luck

On Friday, February 17, 2023 at 6:32:11 PM UTC+2 Alex Liberzon wrote:

meanwhile, I recommend using scikit-image outside of pyptv to create masked images

On Friday, February 17, 2023 at 12:13:47 PM UTC+2 Alex Liberzon wrote:

please upload also the working folder with some images. especially if you use a multi-camera system we need to think how to implement 2-4 masks to 2-4 cameras 

i think at the moment the mask is not fully implemented, but it is not too long to complete 

Best regards

Alex 

From: ope...@googlegroups.com <ope...@googlegroups.com> on behalf of Chris Xu <chris...@gmail.com>
Sent: Friday, February 17, 2023 11:56:02 AM
To: openptv <ope...@googlegroups.com>
Subject: How to apply mask before tracking paticles