Image Number 11 for United States Patent #7103227.
A method enhances images of a naturally illuminated scene. First, a set of images I.sub.i(x, y) is acquired of a scene. Each image is acquired under a different uncontrolled illumination. For each image I.sub.i(x, y), intensity gradients .gradient.I.sub.i(x, y) are determined, and each image is weighted with weights according to the intensity gradients. The weighted images are then combined to construct an enhanced image I'.