View and preview image files easily, adjust brightness, colors, crop, stretch, and resize.

Freeware programs 32Verseea and Esnuka

A multi-format image viewer and converter; supports more than 140 versions of 40 file formats. Available for MS-DOS and Windows. - Developer's site.

StickyView is a FREE application for viewing your favourite image collections from recursive directories either individually or in a slideshow.

Freeware ansikonverter

IrfanView ... one of the most popular viewers worldwide.