XNView - view and convert hundreds of graphic file types
Sometime back in the early days of Windows, I ran into a free graphic viewing utility called XNView. It's still around and it's still one of the fastest programs for viewing and converting. XNView is fairly small, it installs easily, and it doesn't steal the file associations from other programs.
Quote from the website - Come to discover XnView, a software to view and convert graphic files, really simple to use !
Import about 400 graphic file formats
Export about 50 graphic file formats
Multipage TIFF, Animated GIF, Animated ICO support
Adjust brightness, contrast...
Modify number of colors
Apply filters (blur, average, emboss, ...)
Apply effects (lens, wave, ...)
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...