Hi,
I have homebrew not installed. It don’t mix up well with MacPorts.
gmic has to be build with display support. In any case you have to install XQuartz since the display (and interactive functions) base on X11. Perhaps there is an option in the homebrew formula?
Filter listings are in the Gimp plugin or in the gmic reference http://gmic.eu/reference.shtml http://gmic.eu/reference.shtml
Karsten