1. A three-dimensional measurement apparatus comprising: a first imaging unit for imaging an object; a second imaging unit disposed at a predetermined baseline length from the first imaging unit, the second imaging unit imaging at least a part of the object imaged with the first imaging unit; a feature point detector for detecting a plurality of feature points in at least one of two images of the object taken from a first image capture position with the first and second imaging units; a corresponding point detector for detecting corresponding points in at least one of two images of the object taken from a second image capture position with the first and second imaging units, the second image capture position being different from the first image capture position, the corresponding points corresponding to the feature points; a rotation matrix calculator for calculating a rotation matrix representing angle and direction of rotation of the first or second imaging unit at the second image capture position relative to the first or second imaging unit at the first image capture position; a translation matrix calculator for calculating a translation matrix representing a translation direction of the first or second imaging unit at the second image capture position relative to the first or second imaging unit at the first image capture position; an epipolar line calculator for calculating an epipolar line based on a relative positional relationship between each of the imaging units at the first and second image capture positions, the relative positional relationship being determined by a first rotation matrix, a first translation matrix, and a first virtual translation distance, the first rotation matrix being calculated by the rotation matrix calculator based on the feature points and the corresponding points, the first translation matrix being calculated by the translation matrix calculator based on the feature points and the corresponding points, the first virtual translation distance being an arbitrarily assumed distance between each of the imaging unit taking the image in which the feature points are detected and the imaging unit taking the image in which the corresponding points are detected, the epipolar line being a projection of a direction of line of sight from the imaging unit at the first image capture position to the specific feature point onto the image taken from the second image capture position; an evaluator for evaluating whether each of the epipolar lines passes through the corresponding point corresponding to the feature point, the epipolar lines being calculated with the different first virtual translation distances; and a three-dimensional data calculator for calculating three-dimensional data of the object with the use of the first virtual translation distance assumed for calculating the epipolar line passing through the specific feature point.