I do not use OSX, I use linux but..
This one:
http://cue.yellowmagic.info/softwares/s ... index.html only has Windows binaries and code for compiling yourself. How is your expertise at compiling in OSX?
The originator still has a web page with a separate+ for OSX see:
http://www.blackfiveservices.co.uk/separate.shtmlThis is ancient,version 0.3 from 2005 Very-very unlikely to work.
A better bet if you need to use Gimp is, McGimp 2.8.14 from
www.partha.com which has separate+ already installed.
Other ways
- There is an experimental Krita for OSX.
https://krita.org/en/download/krita-desktop/ open a RGB image, change the color space to cmyk then resave. Might work.
- Use command line ImageMagick can be as simple as, but you do need to handle command lines and icc files.
convert image.tiff -profile sRGB.icc -profile cmyk.icc converted_image.jpg
- An on-line conversion site such as
http://www.rgb2cmyk.org/- If the output format is both CMYK and PDF then look at using the desktop publishing application Scribus.