More advanced programs such as Photoshop and Paint Shop Pro give you a
choice of several reduction methods and optimizations. I use Irfan
view also, and it does a pretty crude job of resizing, and the
resulting file size is always much larger than those produced by more
sophisticated programs.

Irfanview is mostly useful as a quick viewer when you want to go
through a folder of photos. It's not really intended as an editor.


I use IrfanView strictly as a viewer as well. There are indeed any number
of better editors out there. But I have yet to find an editor that's as
quick and easy to use as a viewer as IrfanView. Since I don't use IrfanView
as an editor or resizing tool, I've never compared post-resizing file sizes.
But I just did a resize as a test in both IrfanView and Photoshop Elements
version 3, and you're right, the resulting file size was about double in
IrfanView versus PS Elements.