1. An information processing apparatus comprising: a first acquisition unit adapted to acquire, when a calibration jig which includes a second image sensing device for sensing a physical space on which a second index is allocated, and a first index allocated on the second image sensing device is moved within an image sensing range of a first image sensing device, a plurality of first images sensed by the first image sensing device at a plurality of times; a first extraction unit adapted to extract image coordinates of the first index from each of the first images to acquire the image coordinates of the first index at the plurality of times; a second acquisition unit adapted to acquire a plurality of second images sensed by the second image sensing device at the plurality of times; a second extraction unit adapted to extract image coordinates of the second index from each of the second images to acquire the image coordinates of the second index at the plurality of times; and a calculation unit adapted to calculate a camera parameter of the first image sensing device by using simultaneously the image coordinates of the first index and the second index at the plurality of times, which are respectively extracted by said first extraction unit and said second extraction unit.