Oh, believe me, it does. My company sells image capture and analysis packages that work on everything from individual molecules on a slide to transistors on a microchip to bacteria moving around in a live tissue sample.
The trouble is that these systems tend to run in the four to five figure range. Very basic analysis software might set you back a few grand. They also require some expertise to operate, although there are lots of built in macros and functions to make the job easier - the more expensive the package, the better your tools, naturally.
Obviously, because I work for Olympus, I'm biased in its favor, but one of the packages we sell for this purpose is MetaMorph - http://www.moleculardevices.com/pages/s ... lysis.html
. This runs from $7-10K for the baseline software but is really, really advanced. (Edit: the link is to the manufacturer's page; Olympus is a reseller and our page is here
The specific feature you're talking about is called "particle counting", so some searches on that might turn up more information.
Edit 2: try this Google search: http://www.google.com/search?q=particle ... g+software