A typical photograph taken with a point-and-shoot camera with built-in flash typically leads to unattractive photographs. Surfaces close to the camera are overly illuminated while more distant surfaces are dark and indistinct. This is a result of the quadratic falloff of light intensity from the flash.

We propose a simple technique to digitally correct for these illumination problems. This technique requires a pair of images taken with the flash at different positions. A ratio of these images followed by some simple algebra yields an estimate of depth.

The illumination changes can be corrected by simply multiplying by the square of the estimated distance. On the right are some simulation results. Shown is one of the input images (left) and the corrected image (right).

(Collaborative work with David Martin and Ted Adelson)