|GIMP is the most powerful free photo editor that exists, it appeared way back in 1996, and has been regularly updated since.
GIMP is kind of like a free Photoshop, it can do just about anything Photoshop can. It’s designed to incorporate many of the filters, tools, and photographic effects you get from Photoshop.
You can downloade GIMP from the official GIMP web site.
Several tools are available that perform further, lossless compression on JPEG and PNG files, with no effect on image quality.
FastStone Photo Resizer (Freeware) is an image converter and renaming tool that intends to enable users to convert, rename, resize, crop, rotate, change color depth, add text and watermarks to images in a quick and easy batch mode.
You can downloade FastStone Photo Resizer from the original FastStone web site.