The holes in connected regions as an McRegions.

A McMeasure object.  

object.mrRgnHolesAsRegions

The mrRgnHolesAsRegions Property syntax has these parts:

The measurement Value is an McRegions filled with any “holes” in connected foreground regions. All Value accesses reference the same McRegions object, only its contents change. The McRegion exposed as the Value is a copy of the Holes property.

This is a pixel-based measurement. Holes will for only exist for regions created by the McThreshold.Execute method or McFeatures.SetFromMask method (an assignment to the Holes property will also create holes).

Note that a “hole” and a “nested region” are different things (see the Holes and NestedWithin properties for more discussion).