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 -- Daniel Blair & Eric Dufresne
• LabView based particle tracker -- Optical Trapping Group, Univ. of St. Andrews. This software has a nice feature in that it can differentiate between different types of particles in the same image.
• Stand-alone program -- Ryan Smith & Gabe Spaulding. This program doesn't require you to purchase IDL, MatLab, LabView, or anything other than a computer.
• PolyParticleTracker by 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."

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 IDL macros (updated 9-10-07)
• Click here for extra software (updated 2-21-08)
• New: 3D tutorial and software (updated 8-7-06)

Recent news

• 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: weeks(at)physics.emory.edu