Camera Calibration System and Three-Dimensional Measuring System

A three-dimensional measurement device comprising:

• an image-capturing device;
• a reference panel which is placed near an object of three-dimensional measurement, an image of which is to be captured along with the object;
• a calibration parameter calculator which calculates a coordinate transformation parameter from a coordinate system centered on the image-capturing device to a predetermined global coordinate system;
• a three-dimensional calculator which determines, on the basis of an image captured by the image-capturing device, a three-dimensional coordinate of each point in the image in the coordinate system centered on the image-capturing device;
• and
• a three-dimensional shape-integrating device which transforms a three-dimensional coordinate of each point in an image, captured by the image-capturing device from each viewpoint, in the coordinate system centered on the image-capturing device at each viewpoint determined by the three-dimensional device on the basis of the image to a coordinate of the common global coordinate system by means of the coordinate transformation parameter for each viewpoint calculated by the calibration parameter calculator, and integrates the three-dimensional coordinates, wherein
• the reference panel comprises:
• a plurality of light-emitting markers provided at different positions on the reference panel, each of which can assume two states including a bright state and a dark state;
• and
• a controller which switches the states of the light-emitting markers in accordance with switching patterns which differ from each other and synchronously with switching of frames during consecutive image-capturing operations by the image-capturing device, and
• the calibration parameter calculator comprises:
• a marker-identifying unit which specifies a point corresponding to each light-emitting marker in a frame image on the basis of frame images obtained by consecutive capture, by the image-capturing device, of images of a scene including the object and the reference panel from the same viewpoint, and, for each specified point, matches a changing pattern of brightness and darkness of the specified point between frame images and the switching pattern of states for each light-emitting marker, to thereby identify to which light-emitting marker the specified point corresponds;
• a parameter calculator which calculates the coordinate transformation parameter from the coordinate system centered on the image-capturing device to the predetermined global coordinate system on the basis of each light-emitting marker of the frame image identified by the marker-identifying unit;
• and
• a light projector which projects coding light for active-type shape measurement, wherein
• the light projector and the light-emitting markers are set so that at least a portion of light-emitting wavelength ranges do not overlap;
• the calibration parameter calculator determines, from each frame image consecutively captured by the image-capturing device, an image of a wavelength range which falls within the light-emitting wavelength range of the light-emitting marker and which does not overlap the light-emitting wavelength range of the light projector, and calculates a camera calibration parameter on the basis of the determined images;
• and
• the three-dimensional calculator determines, from each frame image consecutively captured by the image-capturing device, an image of a wavelength range which falls within the light-emitting wavelength range of the light projector and which does not overlap the light-emitting wavelength range of the light-emitting marker, and determines the three-dimensional coordinate of each point in the image in the coordinate system centered on the image-capturing device on the basis of the determined images.