Image capture and analysis
It's plausible that a PIC32 will be able to do this job, but it depends enormously on the details of your recognition algorithm. Here are some possible algorithms you might be intending to implement:


Detect a bright red arrow, which is always the same size, in a well lit scene of completely non-red objects.
Detect a bright red arrow, which is can be different sizes, in a well lit scene of completely non-red objects.
Detect a reddish arrow, which is can be different sizes, in a poorly lit scene of objects, many of which of which might also be red, and where the background might also be red.


The first one would be a much simpler algorithm than the last.

Whatever you do, you'll have to take quite a bit of care with you use of memory and processing resources. The PIC32s have a maximum of 128k memory, which should be enough to store the image:

320x240 = 75kB.

...as long as you only store the hue component. Alternatively, you may be willing to store a lower resolution image with 24-bit colour.

160*120 = 56kB.

If you can give us some details of the exact nature of the recognition, and the algorithm, we may be able to help more:


Have you implemented this already on a PC?
Is the arrow always much redder than the background?
Will the arrow always be the same size on the image?
Will it always be the same arrow? Or might it be a hand-drawn arrow?