Information processing method and device

An information processing device for calculating a position of a marker provided upon an object in an object coordinate system using the object as a reference, the device comprising:

• an object position-and-orientation obtaining unit adapted to obtain a position and orientation of the object;
• an image input unit adapted to input an image from a bird's-eye view of the object;
• a detecting unit adapted to detect the marker from the image and obtain a real value of an image coordinate of the detected marker;
• an image coordinate calculating unit adapted to calculate an ideal value of the image coordinate of the marker based on the position and orientation information of the object in the world coordinate system and a state vector representing the position of the marker in the object coordinate system;
• a correction value calculating unit adapted to calculate a correction value of the state vector based on a difference between the real value and the ideal value of the image coordinate of the marker;
• and
• a marker position calculating unit adapted to calculate the position of the marker with in the object coordinate system by correcting the state vector representing the position of the marker in the object coordinate system with the correction value.

A computer-storage medium having a computer-executable program stored thereon for executing an information processing method for calculating a position of a marker provided upon an object, as to the object, the information processing method comprising:

• an object position-and-orientation obtaining step for obtaining a position and orientation of the object in a world coordinate system;
• a first image input step for inputting a first image from a bird's-eye view imaging unit, photographed from a bird's-eye view of the object;
• a detecting step for detecting the marker from the first image and obtaining a real value of an image coordinate of the detected marker;
• an image coordinate calculating step for calculating an ideal value of the image coordinate of the marker based on the position and orientation information of the object in the world coordinate system and a state vector representing the position of the marker in the object coordinate system;
• a correction value calculating step for calculating a correction value of the state vector based on a difference between the real value and the ideal value of the image coordinate of the marker;
• and
• a marker position calculating step for calculating the position of the marker in the object coordinate system by correcting the state vector representing the position of the marker in the object coordinate system with the correction value.