[PD] color tracking in Gem/Pd-extended?

[John Harrison]

Wondering the best solution for color tracking in Pd-extended. I'd like 
my solution to be cross-platform so that rules out PDP and friends.

All I've come up with is to use [pix_blob] to track the color, and to 
try to minimize the tracking color in the background. There's probably a 
Gem object where I can "gate" a color i.e. eliminate a color from a 
pixel if it is less than a certain amount. In my rendering chain after 
my webcam I'd gate the color I am trying to track, then use [pix_blob] 
with a color weight of entirely the tracking color.

Is there a better way?

-John