INFORMATION PROCESSING DEVICE, INFORMATION PROCESSING METHOD, AND PROGRAM

To enable recognition of a posture relationship between an imaging unit and a detection unit in a more favorable mode.An information processing device includes an acquisition unit configured to acquire an image captured by an imaging unit and a detection result of a gravitational acceleration by a detection unit supported by the imaging unit, for each of a plurality of viewpoints different from one another, an image processing unit configured to extract a plurality of line segments extending in a gravity direction from the image and specify an intersection of straight lines obtained by respectively extending the plurality of line segments on the basis of a subject captured in the image for the each viewpoint, and a calculation unit configured to calculate a relative posture relationship between the imaging unit and the detection unit on the basis of the detection result of the gravitational acceleration acquired for each of the plurality of viewpoints and the intersection specified for the each of the plurality of viewpoints.