THREE-DIMENSIONAL MEASUREMENT APPARATUS, PROCESSING METHOD, AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM

A three-dimensional measurement apparatus selects points corresponding to geometric features of a three-dimensional shape model of a target object, projects a plurality of selected points corresponding to the geometric features onto a range image based on approximate values indicating the position and orientation of the target object and imaging parameters at the time of imaging of the range image, searches regions of predetermined ranges respectively from the plurality of projected points for geometric features on the range image which correspond to the geometric features of the three-dimensional shape model, and associates these geometric features with each other. The apparatus then calculates the position and orientation of the target object using differences of distances on a three-dimensional space between the geometric features of the three-dimensional shape model and those on the range image, which are associated with each other.