| Provided are a three-dimensional measurement device, etc., capable of shortening the amount of time required to measure a three-dimensional geometry of a measurement target by shortening the exposure time of an imaging unit. This three-dimensional measurement device is provided with: a projection unit which projects patterned light onto a measurement target; an imaging unit which captures, in a prescribed exposure time, images of the measurement target onto which the patterned light has been projected; a calculation unit which calculates, on the basis of a plurality of feature points included in each of the images, the positions of a group of three-dimensional points representing the three-dimensional geometry of the measurement target; and a determination unit which determines the exposure time so that the number of feature points and/or the number of three-dimensional points in the group is equal to or greater than a threshold established on the basis of the maximal value of one of the two numbers, and that the exposure time becomes shorter than an exposure time corresponding to the maximal value. |
