[vtkusers] vtkImageClip vs. vtkExtractVOI

[Sean McInerney]

Hi all,

Would anyone care to discuss the relative merits of vtkImageClip and 
vtkExtractVOI? ... I want to be sure the subtleties are not lost to me ;-)

I understand that:

1.  BOTH allow specification of an image subvolume by extent indices.

2a. vtkImageClip can pass the input through to the output modifying only 
the whole extent rather than creating a new subvolume output image.

2b. vtkExtractVOI can subsample the input via axis index "strides" (I 
assume that the data spacing of the output correctly reflects this).

Am I missing something or are these the only differences? Are the 
algorithms of each different enough to warrant two classes or is the 
existence of both historical in origin?

-Sean