We handle a lot of images here at Landwave. Our favorite tool for that is Fireworks (RIP). Part of the Adobe suite (nee Macromedia), Fireworks was a lightweight image editor with just enough capability to do composition and works really well for wireframing apps and web sites. Like most apps, you could record macros and write programs to control it. We found that feature useful.
Fireworks API allows you to build custom command panels. We have built several here at Landwave to help with our workflows. One in particular makes us giddy enough to share: the Crop & Scale Panel.
You can download the panel here. Put it in your Fireworks Command Panel folder, restart Fireworks and enjoy cropping and resizing.