There's probably pretty good reason this specific bit went open source. The vision tracking community usually tends to make leaps and bounds on open source projects. People will easily be downloading openCV and modifying it in different ways for their home projects. These modifications will then be usefull to darpa.
Considering that the vision tracking isn't a core function of one of their devices they probably aren't as interested in hoarding it. Why not let some other people do the work?
As we unveil EE Times’ 2015 Silicon 60 list, journalist & Silicon 60 researcher Peter Clarke hosts a conversation on startups in the electronics industry. Panelists Dan Armbrust (investment firm Silicon Catalyst), Andrew Kau (venture capital firm Walden International), and Stan Boland (successful serial entrepreneur, former CEO of Neul, Icera) join in the live debate.