1. A method for detecting ambient conditions of a scene represented by a sequence of images comprising the steps of: generating a reference image containing background information regarding the scene; comparing, pixel-by-pixel, each of said images in said sequence of images to said reference image; classifying, in response to each comparison, the pixels of said images as either background or non-background; comparing a brightness measure of each non-background pixel, computed over a neighborhood of pixels local to that pixel, against a threshold; and processing each non-background pixel to determine the ambient conditions of the scene by classifying, in response to said comparison, each of said non-background pixels as either bright or dark; comparing an energy value of each pixel in said image to an energy value in each pixel of said reference image; determining a mean energy difference of all bright non-background pixels and a mean energy difference for all dark non-background pixels; and processing the mean energy difference of the dark and bright pixels to determine if the scene contains shadows.