[vtk-developers] allow transparency in vtkImageAppend

[Dominik Szczerba]

Hi,

I am appending multiple image blocks using vtkImageAppend. I need to
use PreserveExtents = 1. My image blocks are overlapping and in some
cases undesired overwriting takes place, e.g. when one of the blocks
needed to be rotated/resampled. I am aware I could by hand create a
target canvas of appropriate size and use vtkImageMathematics with
proper masks, but that's just so much more coding and likely also much
performance overhead. What I have done is added concept of
transparency to the said vtkImageAppend, such that copying the data
only takes place if the value is not declared transparent (integer) or
does not lie within a range declared as transparent (floating).

I was wondering if this could be merged with the current development
version. If yes, I can provide a (very simple) patch along with a test
data.

Best regards,
Dominik