Rank filters

[Stéfan van der Walt]

Hi everyone,

We just merged an exciting new rank filtering module, implemented by
Olivier Debeir and guided through review by Johannes Schönberger.
These filters work on the principle that, as a sliding window moves
over an image, its histogram can be efficiently updated by considering
only new values introduced (and left behind) by the moving footprint.

Here are some examples from the gallery:

http://scikit-image.org/docs/dev/auto_examples/applications/plot_rank_filters.html

Enjoy!

Stéfan