Microparticles are in a solution and transferred to a well. They are viewed through an inverted microscope. As the particles begin to move on laser irradiation they have different velocities. How can I measure the velocity of the particles. Since there are a lot of particles doing it by hand would take too long. Tracking the particles is an idea. Is there a simple way to track particles using low cost software or even open source software?
If you are a Matlab user you might want to check out PIVlab or PTVlab, which is available through the Matlab file exchange. In general, PIV is more suitable for high seeding densities, whereas PTV is best for low seeding densities. Another option would be to use OpenPIV, which is freely available.
Agree with Rogier, you need to to choose between PIV and PTV according to the particle density. If you have access to commercial solutions, DynamicStudio from Dantec is a good choice.
Thanks for your answers. Usually, there is low particle density; I guess I should use PTV.
To produce velocity fields I worked with:
http://pivlab.blogspot.de/
And there is a simple ImageJ/Fiji plugin for PTV I also used for close to wall measurements. This is good if you really want to know the velocity of specific particles with low particle densities.
http://mosaic.mpi-cbg.de/ParticleTracker/
Although it's not its purpose, I've already used Blender (free open source software) to do particle tracking in some micro-fluidic experiments. It has a camera tracking tool which allows to track image features along a video or image sequence, which I've used and obtained in some cases better results than with Matlab libraries.
You will not obtain a velocity field but will get the position of each particle that you want to track for every frame. you can then compute velocity from the time between frames.
If you want to give it a try, check for blender camera tracking tutorials just to see how the workflow is and then you can use this script to export the particles positions:
http://scummos.blogspot.pt/2012/11/blender-exporting-camera-tracking.html
http://scummos.blogspot.pt/2012/11/blender-exporting-camera-tracking.html
Here's a short tutorial on how to do Particle Tracking with Blender. Hope it is useful for someone else. https://www.youtube.com/watch?v=eJk-78r6lGM
OpenPIV and OpenPTV are the two options to consider. www.openpiv.net and www.openptv.net
also a trackpy is a good option, see on Github.
Anyone looking for particle tracking software should check out the Neural Network Tracker (NNT) at aitracker.net. It's a web app for automating particle tracking using a convolutional neural network developed at UNC Chapel Hill.
We have a little project which you might find useful. It is a completely gui based tracking tool that implements a few different tracking methods and integrates them with some analysis tools to preprocess the images and calculate quantities and visualise the tracking. It is written in python, open source and easily extendable though to give it a try we've created some (rather bloated!) precompiled versions tested on Windows and Ubuntu. These will allow you to give it a try with the tutorial examples. You should be able to work out if it fits your needs in about 30 minutes. One of the methods implemented is the trackpy library mentioned above. We also use the OpenCV contour finding and Hough Circles algorithms. Full details can be found at our readthedocs page:
https://particle-tracker.readthedocs.io/en/master/
the precompiled versions are available here:
www.nottingham.ac.uk/~ppzmis/software.html
and the project is hosted here:
https://github.com/MikeSmithLabTeam/particletracker
hope this helps you or anyone else with the same question.
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