FILEminimizer Pictures - FILEminimizer Pictures compresses JPEG photos, TIFF, BMP and PNG images and pictures by up to 98%.
Photo Size Optimizer - Photo Size Optimizer for Mac is a powerful photo resizer and optimizer to optimize photos by 80% ~ 20%.
TinyPNG - Make your website faster and save bandwidth. TinyPNG optimizes your PNG images by 50-80% while preserving full transparency!
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Compressor.io - Optimize and compress your images online. Compressor is a lossy and lossless photo compression tool.
FastStone Photo Resizer - Convert and Rename images in batch mode Support JPEG, BMP, GIF, PNG, TIFF and JPEG2000