> Did you see the recently added keyspillm0pup from Marko?
Yes, but haven't tried it yet. The method my plugin utilises has 0
parameters and is 100% effective, but also always introduces color
error that has to be compensated for (it also loses lightness and
detail in the image if it is in the limited channel). They're very
probably both appropriate, more complicated methods need to be used if
the channel limiting used by my plugin is not sufficient.

Channel limiting is generally "good enough" though, here's example
image with unsuppressed on the left, suppressed and color corrected on
the right:
http://i.imgur.com/7tKJU.jpg

> and Makefile.am for the automake build system we still support
True, .../scr/filters/Makefile.am needs to be updated too when these
are included.