target detection drops off with distance

[nathanww]

Hello all,

In working with the ellipse/target detection code, we've discovered an interesting issue: if the camera is positioned within about 12 feet of the vision target, it gets a very stable lock on it. However, if the camera is moved back, target detection becomes very erratic. We're currently using very loose parameters, and the code is detecting ellipses smaller than those on the target. It is also sometimes detecting the two concentric ellipses on the target, but refusing to recognize them as a target(it just sees two circles). Does anyone have any idea why this could occur, or what parameters we could change?