1. A method of recalibrating a depth image sensor, the depth sensor capturing image data from a 3-D space, the method comprising: (a) measuring a depth value of at least one sample point in the 3-D space using the depth sensor; (b) determining a true depth value of the at least one sample point independently of the measurement of said step (a); (c) modeling a depth error resulting from a deviation in the true depth determined in said step (b) and the depth measured in said step (a); and (d) correcting the depth measurements made by the depth sensor using the depth error modeled in said step (c).