Turn scanned negative images into positives

Current version

negfix8 requires the following formula to be installed:
imagemagick 7.0.7-4 Tools and libraries to manipulate images in many formats

Formula history

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)