ImBatch is a reputed image file editor and converter with lots of functionalities -- acceptance of command line parameters deserves highlighting, for example; it can be easily (Uni)extracted, but sadly it stores it's settings at 'HKCU\Software\High Motion Software\ImBatch', making it non-portable...
http://www.highmotionsoftware.com/products/imbatch wrote:ImBatch is a free image processing tool for your Windows PC. With the help of ImBatch, users can perform a variety of complex image editing tasks; applying those changes to hundreds of images at once. Whether you’re looking to crop, resize, rotate, add/remove tags or convert image format, ImBatch provides users with dozens of editing tools.
Latest ImBatch release (currently v3.6.0) changelog and download is at www.highmotionsoftware.com/download-center/imbatch.