[vtk-developers] 64-bit indexing of vtkImageData
ken.martin at kitware.com
Tue Jan 18 09:12:01 EST 2005
> 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
In general this sounds good and makes sense. Certainly increments (and
related number of cell type values) should be vtkIdType.
You are right that extents/coordinates are more of a question. We clearly
should support images with more than range-of-int cells. Do we want to
support datasets that have more than range-of-int pixels on a side? Beats
me. I have a hard time imagining an image that is more than 2 gigapixels on
one axis but maybe others have comments ideas?
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