Apps with 'Batch image manipulation' feature
GIMP is a free program for such photo retouching, image composition and image authoring. Essentially it's the closest thing to Photoshop you can get for free.
Comprehensive photo management software for viewing, batch converting, editing and resizing images and creating thumbnail sheets.
ImageMagick is a software suite to create, edit, and compose bitmap images.
Leading collaboration software and enterprise wiki for intranets and knowledge management.
With BIMP you can apply a set of manipulations to an entire group of images! It provides an easy to use interface and a lot of batch functions.
Cloudimage is a is the easiest way to resize, store, compress, optimize, and deliver your images to your customers through rocket fast CDNs. Faster images increase conversion and sales.
PhotoBatcher is a photo batch application that makes it easy to convert, resize, rotate, color control, apply effects, add watermark and rename photos in a single operation. It supports all popular formats.