Use Pillow-SIMD for better performance/quality

[slint]

The PIllow-SIMD fork seems to be providing some significant perfromance boosts for a couple of operations performed by the IIIF spec (especially faster quality resizing using the PIL.Image.ANTIALIAS algorithm).

From the README of the repo it also seems to be used on production systems already, so it should be stable.

Some benchmarks might be required to get a better image (pun intended).

[greut]

Or pyvips8

• https://github.com/jcupitt/libvips/tree/master/python
• https://github.com/jcupitt/libvips/wiki/Benchmarks

It's much harder to install though

[greut]

http://libvips.blogspot.com/2017/09/new-python-binding.html

[greut]

my current attempt with pyvips, https://github.com/greut/aio-iiif