June 2003

Prototype

Continued from page 1

By Technology Review

Picture Perfect

Even Ansel Adams struggled with light, employing tricky developing techniques to preserve detail and avoid large areas of a print appearing washed out or too dark. Now, amateur photographers can produce artfully balanced images with a new digital-processing algorithm.

Developed by MIT computer scientist Frdo Durand, the process reduces excessive contrast in the picture without losing detail and takes only a couple of seconds. It starts with a digitized image, either from a digital camera or a scan of a negative, and partitions the image data in unique ways. The first partition is into color (which the algorithm does not touch) and light-intensity components. The computer next subdivides the intensity component into one comprising the picture's details and one containing a map of large-scale variations in luminosity. The algorithm then reduces the variations in this final component. Durand hopes the technology will first be employed in software that digital photographers use to download their pictures from camera to computer, which could transform those vacation snapshots from awful to art.