DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Optimage - Advanced image optimization tool
Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats
ImageOptim API - Web service for image compression
Ralpha Image Resizer - High-speed image batch conversion tool
Imagify - Optimize and resize images online and through your CMS.