To perform robust position and orientation measurement even in a situation where noise exist, an image including a target object is obtained, an approximate position and orientation of the target object included in the obtained image are obtained, information related to a shadow region of the target object in the obtained image is estimated, the approximate position and orientation are corrected on the basis of the estimated information related to the shadow region, and a position and orientation of the target object in the image are derived on the basis of the corrected approximate position and orientation and held model information.
