ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
Photopus Pro - Photopus Pro is an easy to use batch image processing to simplify the process to convert, add watermarks (text and image), resize, transform, touch-up, rename, and apply effects to your digital images.
Ralpha Image Resizer - High-speed image batch conversion tool
GraphicConverter - Graphic Converter for Mac and Windows, can converts image formats BMP, JPG, GIF, ICO, PNG, TIF...
Batch Image Resizer - Resize, crop, shrink, flip, exif-rotate, convert, enhance, process multiple pictures and photos with professional software! 120+ Actions, 30+ Image Formats
BatchPhoto - BatchPhoto is a batch photo editing software for Win and Mac that can convert, resize, annotate and watermark hundreds of photos in one go. Learn more and try it for Free!