1. An apparatus for measuring a three-dimensional shape of an object comprising: an image capturing unit configured to capture an image including the object; a change region extraction unit configured to extract a change region where a change has occurred from a previously captured image including the object previously captured by the image capturing unit since a previous measurement of the three-dimensional shape of the object, based on the image captured by the image capturing unit; a setting unit configured to set a stripe pattern which includes a bright portion and a dark portion and in which at least one width of the bright portion and the dark portion is smaller than a width of the change region extracted by the change region extraction unit, from a plurality of stripe patterns in which at least one width of the bright portion and the dark portion is different between the patterns; a projection unit configured to project the set stripe pattern onto the object; and a measurement unit configured to measure the three-dimensional shape of the object at the change region in an image captured by the image capturing unit, where the change region is projected with the set stripe pattern.