How to reduce captured image size without losing resolution?

Hi all,

I've used RoboScreenCapture extensively in caputring web application screen shots for my webhelp pages. However, I'll be creating another manual soon that will require smaller sized versions of screen shots, both as a preference by my co-workers and to minimize space and topic length. Does anyone know of a good way to accomplish this and still maintain quality images?

I've tried editing and resizing, but the resolution becomes distored.

Thanks!