Using a Simple Color Constancy Method for Indoor and Outdoor Applications

Color constancy is a problem of hard solution, and most of existing theories are applied only to synthesized images, while others present a limited performance when applied to real images. In this paper, we apply and analyze a color constancy algorithm that is used with real images subjected to sudden changes in illumination, both in outdoor and indoor environments. In this algorithm, by knowing the colors of some points on the scene submitted to a standard illumination, scene image color correction is made so that it appears always to be under the standard illumination influence. The method employed in this paper is applied to some tasks, such as tracking colored targets, controlling a robot using visual information and pre-processing outdoor images to help on place characterization. Moreover, the algorithm implemented in this work is camera independent because it does not depend on the camera-sensitive responses. The only requirement is that the camera responses can be approximated by the CIE XYZ $$2^o$$2o standard observer functions. The experimental results are discussed and analyzed in order to evaluate the performance of the color constancy method.