I recently updated some x11 packages using swaret on Slackware. It seems to have broken the ImageMagick convert utitility, at least that is my guess since I haven't noticed any other updates in ...

You can use the convert command that comes with ImageMagick to extract parts of an image. You can cut out a 100-pixel-wide chunk from somewhere in the middle of an image: $ convert -crop 100x+0+0 orig ...