Free software for CMYK image conversion/editing?
I've got some RGB images I'd like to print, at local printer and on print on demand sites. Apparently I need to convert to CMYK for best results. Is there good free software where I can convert RGB to CMYK and then adjust the saturation, contrast, brightness etc (as CMYK)? Thank you.
(So far I only know of Scribus, but seems it can only save as CMYK, not adjust the levels.)