🤑 Indie game store🙌 Free games😂 Fun games😨 Horror games
👷 Game development🎨 Assets📚 Comics
🎉 Sales🎁 Bundles
(Edited 2 times)

It ain't very impressive but here:

minmax.lua - Sets White and Black/Max and Min values

Turn on auto to automatically get the highest and lowest value, or you can fine-tune it manually.

http://pastebin.com/jaiCKrr4

edit: Just noticed navot's brightness node already has a Min/Max. Oops.