Query regarding rescaling of data

[akkupant]

Dear Dr. Higham,

I hope this message finds you well. Firstly, I'd like to extend my gratitude for developing the particle tracking toolbox. It appears to hold great promise for my research endeavours, particularly in my exploration of thin film dynamics on water surfaces.

Attached are images that I believe could assist in addressing my queries. In my recent experiments, I've utilised the toolbox to process video footage captured at a high frame rate of 800 fps. Here's a breakdown of my process:

1.) I begin by working with images sized at 1376 x 857 pixels, providing the necessary scaling factor (pix/mm) at the outset of processing.

2.) Subsequently, I opt for a grid size of 172 x 107.

The output from the toolbox yields vector fields presented as a 172 x 107 matrix (not scaled in mm on x and y axes). Please see image 2

However, I find myself pondering two key points:

Should the vector fields be rescaled into millimetres separately or should the code provide scaled values of UX and UY ( in mm/s or m/s).

Given that the code does not provide x and y data as part of its output, should I manually derive this information based on the scaling factor?

I appreciate any guidance or insights you can offer on these matters. Thank you for your time and consideration.

Warm regards,
Anurag Pant (PhD)