Abstract
A method of the present disclosure includes (a) extracting distinctive features used for respectively distinguishing a plurality of similar attitudes from which images similar to one another are obtained using a simulation model of an object, (b) capturing an object image of the object using a camera, (c) estimating a position and an attitude of the object using the object image, and (d) when the estimated attitude corresponds to one of the plurality of similar attitudes, determining the one of the plurality of similar attitudes as the attitude of the object using the distinctive features.