This is intended for scikit-image v1.0:

• Replace PIL dependency with imageio
• Import all of imageio API into skimage.io namespace.
• Move ImageCollection to imageio
• Keep image stack
• Remove external.tifffile
• Use matplotlib only for show.

I have added plugins to imageio for tifffile, gdal, fits, and itk.

imageio only depends on libfreeimage, which is included in Debian repos, and will be included within the wheel installs for OSX and Windows. There is a cross-platform conda recipe for libfreeimage.

Benefits:

• No PIL!
• Plugins are selected based on file extension, but can be overridden.
• A sane API for multi-image read/write.
• We benefit from any additional plugins that are added.