

First install imagemagick. I found it in the APT repositries. Its fairly straight forward to install. Then using a terminal use this command
mogrify -resize 24x24 *.png, making sure that you have used the cd command to go to the directory your icons are in. For example:-
$ cd home/richard/.icons/aer-os-xk/128x128/apps
$ mogrify -resize 24x24 *.png
and it converts your icons to 24x24 size or whatever you want it to be, just change the 24x24 to 32x32 or 48x48, you get the idea! - Jun 29 2008
mogrify -resize 24x24 *.png, making sure that you have used the cd command to go to the directory your icons are in. For example:-
$ cd home/richard/.icons/aer-os-xk/128x128/apps
$ mogrify -resize 24x24 *.png
and it converts your icons to 24x24 size or whatever you want it to be, just change the 24x24 to 32x32 or 48x48, you get the idea! - Jun 29 2008