[vtk-developers] 64-bit indexing of vtkImageData

[David Gobbi]

Hi All,

When VTK was switched over to vtkIdType so that 64-bit indices into data
arrays became possible, vtkImageData was overlooked and even in VTK 4.5 it
isn't possible to have image data over the 32-bit size limit.

I'd like to add 64-bit image indexing before VTK 5 is released, and I
want to solicit comments about how aggressive the change should be.
I think that the best approach is for increments to be stored as
vtkIdType, but perhaps extents and any image integer coordinates should
also be converted to vtkIdType.  It isn't absolutely necessary for
extents to be stored as vtkIdType unless people will be dealing with
images that are more than two gigavoxels across in one of the three
dimensions.

Any thoughts?

Also, Glen Lehmann has finished a conversion of VTK 4.4 to 64-bit
image indexing, and we might be able to release it to the public in
the near future.  Would anyone be interested?  I could even commit
it to the VTK 4.4 branch, since the changes didn't involve any of
the header files.

--
  David Gobbi, PhD
  Lead Software Developer
  Atamai Inc. (www.atamai.com)