Patent ID: 7574043

Claim:
A method for modeling a scene, comprising the steps of: acquiring a video of a scene with a camera, and for each frame of the video: in a computer: updating, for each pixel, a set of background models; representing the pixels in each background model and each shadow model with a plurality of layers, each layer including a plurality of Gaussian distributions, each Gaussian distribution including a mean and a covariance, the covariance being an inverse Wishart distribution, and the updating is according to a recursive Bayesian estimation process; updating, for each pixel, a set of shadow models; updating, for each background color, a set of shadow flow vectors from the set of shadow models; determining, for each pixel, a confidence score for each model; comparing, for each pixel, a most confident shadow model with a most confident background model to determine a disparity vector; projecting the disparity vectors into a quantized color space including bins, each bin representing a color value in a background of the scene; and aggregating, for each bin, the projected disparity vectors to locate the shadow flow vector in each bin; and updating, for each pixel, a background shadow map using the set of shadow flow vectors to detect shadows in the video.