Registration with only one histology slice

[mirabelarusu]

Bug related to output of the "3D" RGB image, it converts it into a 2D RGB image and thus looses spacing and origin on the third dimension.

Seems to be a bug with WriteImage that makes the conversion internally.

Possible (not ideal) work around: copy the histology on a second slices to have a real "3D" image

[mirabelarusu]

3D Slices has the same issue. So this is likely a SimpleITK/ITK issue.