An information processing device for obtaining placement information
regarding an imaging device of markers to be calibrated that are provided
upon the imaging device, includes: a first image obtaining unit adapted
to obtain a first image photographed with the imaging device; a second
image obtaining unit adapted to obtain a second image obtained by
photographing the imaging device from a bird's-eye view position; a first
detecting unit adapted to detect information relating to image
coordinates of reference markers placed in a scene, from the first image;
a second detecting unit adapted to detect information relating to image
coordinates of markers to be calibrated from the second image; and a
calibration information calculating unit adapted to obtain the
calibration information using information relating to image coordinates
of the reference markers detected by the first detecting unit and the
second detecting unit.