PROBLEM TO BE SOLVED: To achieve accurate calibration on an AR system using an optical see-through type HMD with a small number of pointing actions.SOLUTION: A camera position attitude estimation part 43 estimates a position and an attitude of a camera 3. A 3D-2D correspondence configuration part 44 calculates three-dimensional coordinates of one point of a marker coordinate system on a camera coordinate system on the basis of the position and attitude of the camera 3. Further, a user is requested to make a pointing action, two-dimensional coordinates of the one point on a screen plane when the point is seen to the eyes of the user through a screen 2 are acquired, and coordinate between three-dimensional coordinates and two-dimensional coordinates is configured as a set and output to an on-line parameter estimation part 45. An on-line parameter estimation part 45 compensates deficient information with previously acquired off-line parameters so as to estimate calibration parameters, which are computed from six
