IM 6.4.3-4 Q16 Mac OSX Tiger
-extent does not seem to honor -gravity center
convert rose: -gravity center -extent 100x100 rose_center.png
the rose image ends up in the top left corner
potential bug -extent IM 6.4.3-4
Re: potential bug -extent IM 6.4.3-4
The problem you reported is fixed in the latest ImageMagick subversion trunk and will be available in the next point release. Thanks.