1. An image processing apparatus comprising: a video input unit; a region division unit configured to divide an image acquired by said video input unit into a plurality of regions each including pixels of similar attributes; a feature extraction unit configured to extract a feature from each region divided by said region division unit; a background model storage unit configured to store a background model generated from a feature of a background in advance; and a feature comparison unit configured to compare the feature extracted by said feature extraction unit with a feature in the background model and determine for each of the plurality of regions whether the region is the background.