Turn scanned negative images into positives

Current versions

negfix8 requires the following formula to be installed:
imagemagick 7.0.7-27 Tools and libraries to manipulate images in many formats

Recent formula history

ilovezfs negfix8: use assert_predicate
FX Coudert negfix8: remove old imagemagick option
Xu Cheng negfix8: bottle unneeded
Nikolaus Wittenstein Clean up existing descriptions
Simon Bugert negfix8 8.3 (new formula)

Formula code at GitHub