The imagemagick site has a demo on this page: http://www.imagemagick.org/Usage/resize/#resize
I want to perform the action in this example:
convert logo: -resize 80x80\> \
-size 80x80 xc:blue +swap -gravity center -composite \
space_resize.jpg
But for a large number of files. I think the right tool is mogrify, but it does not know the +swap or xc:blue flags.
Advice?