I have been looking into an issue with the vtkTIFFReader, and commit 84f9a173d81 made by @lorensen in 2014. The line that confuses me is:
const bool flip = this->InternalImage->Orientation != ORIENTATION_TOPLEFT;
This is opposite to what I would expect, where vtkImageData
has its origin in the bottom-left, and so with an orientation in top-left I would expect that to cause the image to be flipped, i.e. ==
rather than !=
. Is there something I am missing. In a simple test I get a single page TIFF, and it is flipped opposite to what my system viewer renders in Tomviz.
I can propose a patch making all of these ==
and it would fix my issue, maybe there is something about tiled TIFFs I don’t appreciate (I use multi-page, but not tiled).