FastStone Image Viewer, Fast, Powerful, and Free Image Viewer
Have you ever used ACDSee? I used that Image Viewer and I like that because it is easy to use. I can view my photos, and at the same time I can edit it. I can crop, resize, adjust the brightness and contras, add effect like sephia, etc. Unfortunately, ACDSee is not a freeware, we should pay some money if we want to use it. If you a powerful, fast, complete, and free image viewer, You can use FastStone Image Viewer.
FastStone Image Viewer has been rated 5 stars by CNET editors at Download.com, so I think it is a good software. FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor. It has a nice array of features that include image viewing, management, comparison, red-eye removal, emailing, resizing, cropping, retouching and color adjustments. Its innovative but intuitive full-screen mode provides quick access to EXIF information, thumbnail browser and major functionalities via hidden toolbars that pop up when your mouse touches the four edges of the screen. Other features include a high quality magnifier and a musical slideshow with 150+ transitional effects, as well as lossless JPEG transitions, drop shadow effects, image annotation, scanner support, histogram and much more. It supports all major graphic formats (BMP, JPEG, JPEG 2000, animated GIF, PNG, PCX, PSD, EPS, TIFF, WMF, ICO and TGA) and popular digital camera RAW formats (CRW, CR2, NEF, PEF, RAF, MRW, ORF, SRF, ARW, SR2, RW2 and DNG).
You can download from http://www.faststone.org/download.htm
If You are using linux, gthumb is a good image viewer. Try this.