%[filename:
at the source code
case
%d
%[
]
developer forums
filename:mysize
$ convert rose: -set filename:mysize "%wx%h_%p" rose_%[filename:mysize].png
#=> rose_70x46_0.png
$ convert rose: wizard: -set filename:mysize "%wx%h_%p" rose_%[filename:mysize].png
#=> rose_70x46_0.png rose_480x640_1.png