Pontifications

If you don’t want the filepath and you don’t want the filetype use {/.} which is the “Basename of input line without extension.” according to the man page.
example:

cd /home/roland/GIT/rt-mozlando2018-ksc/264x176
parallel convert {} -resize 264x176! 264x176-{/.}.png ::: ../ORIGINALS/*.jpg    
mkdir MONOCHROME ; cd !$
parallel convert {} -monochrome monochrome-{/.}.gif ::: ../*.png

previous blog posts about parallel:
- Use GNU Parallel instead of xargs to run a script on wildcards and a file that is a list of files
- GNU Parallel to use all your CPU cores