Patent ID: 7388969
Filing Date: 2008-06-17
Classification: G06K,G06T

Abstract:
1. A method of measuring a rotational amount of a body with a curved surface and a direction of a rotational axis thereof, comprising the steps of: photographing at predetermined intervals said rotating body with the curved surface having a plurality of marks given to a surface thereof to obtain a plurality of two-dimensional images of said body with the curved surface; generating an imaginary body with the curved surface having a plurality of marks given to a surface thereof in a three-dimensional coordinate space by operating a computer; setting an arbitrary posture of said imaginary body with the curved surface as a reference posture, observing said imaginary body with the curved surface in an arbitrary viewing direction, and performing a posture displacement operation with said computer in such a way that said marks given to said imaginary body with the curved surface are coincident with said marks given to said surface of said body with the curved surface in each of said two-dimensional images; specifying a three-dimensional posture of said body with the curved surface for each of said two-dimensional images thereof on the basis of an amount of a posture displacement operation, relative to said reference posture; and determining said rotational amount of said body with the curved surface and said direction of said rotational axis thereof by computing a rotation matrix relating to a rotation operation to be performed in making said specified three-dimensional posture of said body with the curved surface at one time coincident with said three-dimensional posture of said body with the curved surface at another time, wherein said posture displacement operation comprises: an operation of magnifying and minifying, moving, and rotating said imaginary body with the curved surface; and an amount of said posture displacement operation relative to said reference posture is found as an amount of said operation of magnifying and minifying, moving, and rotating said imaginary body with the curved surface by computations based on a genetic algorithm.