XnView: "XnView is a utility for viewing and converting graphic files. It has the features :
Import about 400 graphic file formats
Export about 50 graphic file formats
Multipage TIFF, Animated GIF, Animated ICO support
IPTC, EXIF
Resize
Copy/Cut/Crop
Adjust brigthness, contrast...
Modify number of colors
Apply filters (blur, average, emboss, ...)
Apply effects (lens, wave, ...)
Fullscreen mode
Slide show
Picture browser
Batch convert
Thumbnail create
Screen capture
Contact Sheet create
Multi-page file create (TIFF, DCX, LDF)
TWAIN support (Windows only)
Print support (Windows only)
Drag & Drop support (Windows only)
44 languages support (Windows only)
And many many other things..."
XnView is provided as FREEWARE for private non-commercial or educational use (including non-profit organization)
Note : For commercial use and distribution, it is necessary to register. It is a help for the development of future versions. XnView for Linux, FreeBSD are FREE also for commercial use.