How is the interclass variance automatic threshold level calculated?

[roslocke]

The algorithms for the entropy, factor and moment methods of automatic thresholding are well documented in image processing literature but I can't find anything on the interclass variance.

[cld]

I believe this will be simialr to the Clustering technique described in the Vision Concepts Manual
Chris

[roslocke]

Ah, yes. Silly me. It's always a good idea to read the manual.