I wrote a quick simple G’MIC filter. I may add to it later. You may try it out by creating a user.gmic file and placing it in the correct directory:
At startup, G’MIC automatically includes user’s command file $HOME/.gmic (on Unix) or APPDATA/user.gmic (on Windows).
@David_Tschumperle Just added it to gmic-community for me! Just update your filters.
Edited: see date in screenshot.
#@gui Vigrect : fx_vigrect, fx_vigrect_preview(1)
#@gui : Size(%) = int(10,1,25)
#@gui : Blur(%) = int(10,5,20)
#@gui : Opacity = float(.75,.5,1)
#@gui : sep = separator(), note = note("Filter by <i>afre</i>. Latest update: <i>2017-01-05</i>.")
fx_vigrect :
p={min(w,h)*$1/100}
--to_gray -rectangle. {[$p,$p,w-$p,h-$p]}
-f. i==0?0:ia#0 -b. {min(w,h)*$2/100} -*. $3 -- -c 0,255
fx_vigrect_preview :
-fx_vigrect $*