Hi Robert Lancer
Yes and No.
There are lots of computer vision tools as of now, openCV, simpleCV, CCV being the most popular ones in the todays embedded systems development world. So is arduino. But heres the catch, the arduino has low memory, slower processor and much lesser RAM. I also wanted to do some CV with an arduino, and I weighted options for the mega and the yun too. Unfortunately, the obvious won and I had to sadly conclude that its not impossible but maybe not until a better arduino arrives.
I read about an openFramework(oF) sometime ago from sparkfun which claimed to be a framework for arduino using C++ that could greatly increase the media capabilities for the arduino. So you might want to give that a good read. But my suggestion is that you went with other options available here, including Raspberry Pi, for computer vision where we can choose openCV, simpeCV and CCV also.