A change in an angle θ from 0° to 2° will cause the stripe angle in the moiré pattern to change from 0° (a) to 24° (b). (a) 3,062 × 3,730 pixels; (b) selected area from (a), showing grid artifacts. (c) Selected area from (a), with grid artifacts removed. (d) 1-Dimensional Fourier transform of the image in (a). Grid artifact frequency indicated by the circle. (e) The spectrum after grid artifacts are removed. (f) 540 × 648 pixels; (g) 540 × 648 pixels, with grid artifact removed.