Then followed by: osx_prompt$ brew install imagemagick First we run of course: osx_prompt$ brew update To install imagemagick in OSX I highly recommend homebrew. The command we need is convert and it is part of a wonderful open source program called imagemagick. In this day and age one meddling with computers should at least know some basic Linux. If you don’t have at least one Linux distribution at your disposal, it is time to change this. Move all the TIFFs to a single temporary directory that you can access from your command line.