Date of Award


Document Type

Thesis (Undergraduate)


Department of Computer Science

First Advisor

Hany Farid


Digital camera technology has recently seen substantial improvements in image quality while lower prices have made it affordable to the average consumer. Camera manufacturers, however, are not taking full advantage of this new medium for image capture. By filtering the already digitized image produced by these cameras through on-board image processing algorithms we can dramatically increase the power of digital cameras. For example, according to experts in the photographic industry, most people simply take bad pictures. Classic examples of this phenomenon are photographs taken indoors with a point-and-shoot style camera using its built-in flash. The subjects of these photographs often seem to have a spotlight on them, making them look bright and washed out while the rest of the photograph is dark and indistinct. This can primarily be accounted for by a well known property of point light sources: falloff in brightness is inversely proportional to the square of the distance between the light and the object being illuminated. A technique first introduced in the field of computer vision has been shown to successfully recover information about the distance between the light source and objects in the world. We propose using this technique, which is readily implementable in hardware, to correct for a variety of poorly illuminated digital images.


Originally posted in the Dartmouth College Computer Science Technical Report Series, number TR2000-373.