[Insight-developers] Morphological opening and closing

[Lorensen, William E (Research)]

Lino,
 First of all, thank you so much for your contribution. Please look at the
changes that I just checked in. The filters were not using the pipeline
correctly.

1) ThreadedGenerateData should never call AllocateOutputs. For threaded
filters, this is handled in the superclass.

2) The components of the minipipeline are threaded, so the invoking method
should not be.

3) The filters should inherit from ImageToImageFilter.

Once again, thanks for your contributions.

Bill