Patent ID: 8708822

Claim:
A non-transitory computer readable storage medium having stored thereon a program executable by at least one computer of an information processing apparatus for receiving operation data from a handheld operation device including an imaging device for taking images of an imaging target and for displaying, in a display area on a display device, a menu object containing selectable items and enabling a user to interact with the displayed menu object in accordance with calculation processing performed using the operation data, the imaging device taking first and second images, the program causing the at least one computer to perform operations comprising: obtaining a first image taken by the imaging device of the operation device as the operation data; conditionally selecting the displayed menu object as a user-selected operation target based on a position of the imaging target in a taken image; calculating a first two-dimensional vector based on an orientation of the imaging target in the first taken image; calculating a second two-dimensional vector based on an orientation of the imaging target in the second taken image; calculating an angular difference between said first and second two-dimensional vectors, the angular difference indicative of roll rotation of the operation device about an imaging direction axis of the imaging device between the imaging device and the user-selected operation target; calculating a scroll amount, s, based on the calculated angular difference so that the scroll amount has a magnitude that is proportional to the absolute value of the angular difference; linearly scrolling the selectable items within the selected displayed menu object in a predetermined direction by an amount responsive to the calculated scroll amount, s; and allowing the user to initiate an action by pointing the handheld device at and further selecting a scrolled selectable item displayed on the display area of the display device.