I checked on PIL and scikit-image as per @blowekamp suggestion. Bradley is correct in that scikit-image handles operations on 3D images using C-contiguous arrays, where as channels in RGB images go last.
In case you guys are interested, this link explains very clearly the difference between RGB and 3D images in terms of the array layout for scikit-image 4. A crash course on NumPy for images — skimage 0.23.0rc0.dev0 documentation
An excerpt explaining everything is here:
Perhaps adding some like this to SimpleITK’s documentation could be really helpful? What do you guys think?
On the other hand I didn’t find info on PIL other than when you retrieve data from the image, you get a cordinate-less array in the sense that it is a flattened array instead of multi-indexed.
Regards,
Diego