Sudden illumination change detection using order consistency

Effective change detection under dynamic illumination conditions is an active research topic. Most research has concentrated on adaptive statistical representations for the appearance of the background scene. There is limited work that develops the statistical models for background representation by taking into account an explicit model for the camera response function, the camera noise model, and illumination priors. Assuming a monotone but nonlinear camera response function, a Phong shading model for the surface material, and a locally constant but spatially varying illumination, we show that the sign of the difference between two pixel measurements is maintained across global illumination changes. We use this result along with a statistical model for the camera noise to develop a change detection algorithm that deals with sudden changes in illumination. The performance evaluation of the algorithm is done through simulations and on real data.