Particle tracking using IDL

The software described on these web pages was developed by John Crocker and David Grier; Eric Weeks has contributed a few supplemental routines, and has designed this web page. There are some good alternatives to our method:

• Matlab version of these routines -- Kevin Aptowicz.
  These are a 2023 translation that tries to remain faithful to the original Crocker/Grier code.
• Matlab version of these routines -- Daniel Blair & Eric Dufresne
  Caution: The Blair & Dufresne routines are not exact translations of the original code, and so some functionality is missing. See the Kevin Aptowicz code above for the full functionality. If you have questions about using the Blair & Dufresne codes, ask them, not us. Nonetheless, many people are successfully and happily using the Blair & Dufresne MatLab routines, and they are happy to provide user support.
• Trackpy, python implementation of these routines -- by Daniel Allan, Nathan Keim, Thomas Caswell, and others
• GDL version of routines -- Kenneth Desmond. GDL is a freeware version of IDL.
• Stand-alone program -- Ryan Smith & Gabe Spalding. This program doesn't require you to purchase IDL, MatLab, LabView, or anything other than a computer.
• PolyParticleTracker -- Salman S. Rogers, Univ. of Manchester. MatLab scripts. This particle tracking package is "particularly suitable for the tracking of low-contrast particles against a complicated background."
• Thomas Caswell is working to convert our IDL code into C++ -- his website has "pre-beta" code

The method and the software

1. Read in a single frame, then process it interactively to figure out what settings to use to 'find' the particles you want to study.
2. Use a macro to repeat everything you did on all the frames you want to analyze.
3. Link the coordinates found in each frame together to form trajectories.
4. Analyze the trajectory info as you see fit for your particular experiment. You will have to design this part yourself-- since this is the science part!

• Click here for a tutorial
• Click here to download the tracking IDL macros (updated 6-6-11)
• Click here for extra software (updated 8-27-11)
• New: 3D tutorial and software (updated 8-7-06)

Recent news

• 5-26-21: Bug fix of 2D g(r) code (very rare issue caused program to crash)
• 9-29-08: Download of .pro files not working, you can download everything as zip files now.
• 5-30-07: Microhreology code for IDL added
• 10-16-06: See new note about the radius of gyration calculation
• 8-7-06: 3D tracking tutorial written, along with software.
• 7-24-06: Tutorial slightly revised -- most people use readtiffstack these days, revised to reflect this
• 9-9-05: LabView based particle tracker -- Optical Trapping Group, Univ. of St. Andrews
• 7-18-05: Freeware code -- a new website! From Ryan Smith and Gabe Spalding. Does not require IDL or Matlab.

References

• "Methods of Digital Video Microscopy for Colloidal Studies", John C. Crocker and David G. Grier, J. Colloid Interface Sci. 179, 298 (1996).
  • read paper on the web
  • download a copy
• ITTVIS, the people who sell IDL. We're sure they'll be happy to sell you a copy. They get two thumbs up from John and Eric.
• Search the IDL manual.

Contact us

• John Crocker: jcrocker(at)seas.upenn.edu
• Eric Weeks: erweeks(at)emory.edu