We propose focused color intersection with efficient searching for ide
ntifying and extracting the objects in a complex scene based on color
similarity. The method matches the models against different parts of a
scene, called focus regions, using normalized color histogram interse
ction. The best matching focus region is determined by an efficient se
arch strategy employing upper bound pruning. This search strategy, cal
led active search, concentrates its effort on parts of the scene havin
g high similarity with the object. Consequently, it achieves a large r
eduction in computational effort without sacrificing accuracy. An effi
cient algorithm for evaluating the color histogram intersection betwee
n a model and a focus region is also given. Experiments conducted demo
nstrate that multiple known objects in complex scenes can be extracted
by this process. The method is stable against scale changes, two-dime
nsional rotation, moderate changes in shape and partial occlusion. (C)
1997 Pattern Recognition Society. Published by Elsevier Science Ltd.