Photo Enlargement
Enlarging a photo increases its size. A 4-by-6 picture can be transformed into a 16-by-20 poster-size print either in a commercial photo lab, darkroom, or using a home computer and software program.
Digital Photo Enlargement
Unfortunately, you cannot enlarge a digital picture simply by changing its size in the imaging program you use. If you make a low-resolution digital image bigger, the pixels that make up the image become obvious, and the photo will look blurry.
Scanning
One way to improve a photo's resolution so that it can be enlarged is to print out a copy and then scan the copy into the computer using a high (at least 300 pixels per inch) resolution. You can then enlarged the photo without it becoming blurry.
Photo Restoration
It is entirely possible to repair old photos that have been cracked, discolored or faded. A commercial company can restore your photos or you can do it yourself using a scanner and software such as Adobe Photoshop or Windows Live Photo Gallery.
Restoration Basics
Restore photos by lightening or darkening the image, removing scratches and creases, or by cropping out damaged areas. You can also colorize old black and white photos.