Calibration object

摘要

A calibration subject (11, 11B) for providing a reference dimension for use in measuring the surface shape of a measuring object to be photographed in stereo comprises an origin reference point target 110 corresponding to the origin position for three-dimensional measurement and reference targets (113, 113B) arranged in such a manner that at least six of them are included in each of stereo images photographed from a plurality of directions. The positions of the reference targets are determined in advance with respect to the origin reference point target 110.