Patent ID: 8659660

Claim:
A calibration apparatus comprising: a memory; and a processor coupled to the memory, the processor configured to: obtain first and second images captured by two cameras of a plurality of cameras mounted on an object, the first image including images of a first marker set and a second marker set, the second image including images of a first marker set and a third marker set, each of the first, second and third marker sets including a plurality of markers, form a closed-link structure based on a first representative point of the first marker set and a second representative point of the second marker set in the first image, and a first representative point of the first marker set and a third representative point of the third marker set in the obtained second image, the first representative points in the first and second images being matched each other in the closed-link structure, determine a link angle of the closed-link structure when a difference representing a distance between the images of the same marker of the first marker set in the first and second images satisfy a given condition, and determine a parameter for positioning at least one of the plurality of cameras based on the determined link angle, wherein the processor is further configured to form the closed-link structure by detecting the image of the first marker set of the first image and the image of the first marker set of the second image, forming a first line connecting the first representative point which is at a given position in the image of the first marker set and the second representative point which is at a given position in the image of the second marker set in the first image, forming a second line connecting the first representative point which is at a given position in the image of the first marker set and the third representative point which is at a given position in the image of the third marker set in the second image, arranging the lines so that the first representative points in the first and second images are matched with each other, and forming the closed-link structure including the first and second lines through the matched first representative point, the link angle of the closed-link structure being specified by an angle between the first and second lines.