POSITIONING DEVICE, ESTIMATION METHOD, AND NON-TRANSITORY COMPUTER-READABLE MEDIUM

A positioning device includes an acquisition unit that acquires an environmental map of a target area being generated by using an image processing technique for estimating a three-dimensional shape of a target included in a two-dimensional image, and a plurality of captured images being used for generating the environmental map, an image retrieval unit that extracts, from a plurality of the captured images, a similar image having a feature vector similar to a feature vector determined based on a feature amount included in an input image, and an estimation unit that estimates a position and an attitude of an imaging device that has captured the input image by using a first feature point group of the input image and a third feature point group in the environmental map associated to a second feature point group of the similar image being matched with the first feature point group.