A non-transitory computer readable medium having stored thereon a program to be executed by a computer for calibration of at least one projection display device that projects an image onto a projection plane, comprising the steps of:
- capturing an image of the projection plane by an imaging device obtaining from the captured image a first position-data that indicating a set of positions of plural feature points in the projection plane, and projecting a test image onto the projection plane by the at least one projection display device and capturing an image of the test image by the imaging device obtaining from the captured image a second position-data that indicating a set of positions of plural feature points in the test image;
- capturing an image of the projection plane by the imaging device after the obtaining of the first position-data and the second position-data, obtaining a third position-data that indicating a set of positions of the feature points in the projection plane, and projecting the test image onto the projection plane by at least one the projection display device and capturing an image of the test image by the imaging device obtaining from the captured image a fourth position-data that indicating a set of positions of the feature points in the test image;
- obtaining a first deviation-data that indicates a deviation in a relative position between the imaging device and the projection plane on the basis of a difference between the first position-data and the third position-data, and correcting the set of positions of the feature points in the test image contained in the fourth position-data on basis of the first deviation-data to create a fifth position-data;
- and
- obtaining a second deviation-data that indicates a deviation in a relative position between the at least one projection display device and the projection plane on the basis of a difference between the second position-data and the fifth position-data, and calibrating the at least one projection display device on basis of the second deviation-data.