Comics in the format CBZ are supported and naturally also the common uncompressed version.
It converts every images recursive within the passed path and compresses it into a (hopefully) smaller version of the origin.
For now it's only possible to change the quality setting of the convertion into JPEG. If the resulting convertion based on the origin is not smaller the convertion will be deleted to prevent non efficient compression that has a quality that is even worse.
A detailed guide and some more features will follow.