>This may help, you may find a ActiveX or COM wrapper on The Web. http://www.imagemagick.org/

There isn't any wrappers available for it (yet), although you can use the command-line utilities to do this. I'm actually in the process of wrapping ImageMagick into a nice ActiveX/COM control; resizing and converting the images was the first thing I did. It's still a ways away from being complete, but it'll be free once (if) I finish it.

I'd also suggest LeadTools - it has a really nice set of controls that can do this (and a LOT more).