Patent ID: 7224735

Claim:
A method for adaptively updating a background image representing a background of a scene, comprising: selecting, uniformly, a set Q of s pixels in each image, wherein the set Q is Q→{B(x s , y s ,c,t),I(x s , y s ,c,t)|(x s ,y s )=( c 1s ,m,c 2s n) M(x s ,y s ,t)≠1}, B(x,y,c,t) is the background image, I(x,y,c,t) is a particular image, M(x,y,t) is an object mask, c 1s and c 2s are sampling frequencies, c is a color channel, t is a frame number associated with the particular image, and s is a number of pixels in the set Q; determining a similarity score for the set Q of s pixels in each of a plurality images of the scene; and updating the background image only if the similarity score for a particular image is less than a predetermined threshold.