Understanding ImageMagick's convert and translating to Ruby RMagick

Question

I\'m failing at translating the following PHP/ImageMagick code into Ruby RMagick (to make it more manageable for future users and to understand what it\'s really doing):

Answer 1

Posting this for anyone who is still looking for a solution to this, there is a way of doing this in ruby using the rmagick gem described here https://stackoverflow.com/a/41282162/1975112