Particle tracking using IDL
John C. Crocker and Eric R. Weeks
The software described on these web pages was developed
by John Crocker and
Grier; Eric Weeks has contributed a few supplemental routines, and
has designed this web page. There are some good alternatives to
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. You may want to try
Kilfoil's versions which we believe are more similar to the
original IDL-based code. 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
version of routines -- Kenneth Desmond. GDL is a freeware
version of IDL.
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
program -- Ryan Smith & Gabe Spalding. This program doesn't
require you to purchase IDL, MatLab, LabView, or anything other
than a computer.
-- 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."
Caswell is working to convert our IDL code into C++ -- his
website has "pre-beta" code
The method and the software
A quick overview:
- Read in a single frame, then process it interactively to figure out what settings to use to 'find' the particles you
want to study.
- Use a macro to repeat everything you did on all the frames you
want to analyze.
- Link the coordinates found in each frame together to form trajectories.
- 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!
"Methods of Digital Video Microscopy for Colloidal Studies",
John C. Crocker and David G. Grier, J. Colloid Interface Sci.
179, 298 (1996).
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.
The work of Eric Weeks in maintaining and updating this web page
is supported by the National Science Foundation under Grant
No. DMR-0239109. Any opinions, findings, and conclusions or
recommendations expressed in this website are those of the
author(s) and do not necessarily reflect the views of the
National Science Foundation.