Circles detection in grayscale

[seb]

I'd like to detect circles in a 8bit image using the grayscale information (instead of brutally applying a threshold) in order to get sub-pixel accuracy.
Does Labview do that?
Did anybody write a program that does it?
I'm using labview 5.0.1 and Imaq vision.
thanks

[BruceAmmons]

The good news is that it is relatively easy to do. The bad news is that it uses a new tool in IMAQ Vision 6.

There is a tool that will locate the edges of a circle and determine the size and location of the circle. It is called a circular rake. It basically finds edges along radial lines around the circle, then determines the circle parameters.

Bruce