One way to use objects in the pipeline is to use the Object Mask operation.

The Object Mask will black out any pixel outside of the region while preserving the intensities inside:

This can be used to limit the analysis to only within the region since we can easily ignore any pixel with a value of 0, but such image processing can get in the way of several other operations we might want to use in a pipeline because of the artificially hard edge that is created.