Fig. 1
Modeling the effects of a triple-SPM-tip on the image of a p4 source. a A 550 by 550 pixel image whose p4-symmetry is known by design. (Based on its “experimental counterparts” in refs. [6, 13], the area of this image corresponds to approximately 340 nm2). b A “hypothetical image” to model what a triple-SPM-tip would produce when imaging this “sample,” constructed in Photoshop by overlaying two copies of the p4 image, shifting them, and setting the blend mode to Overlay (footnote 2), with the opacity reduced for each to model different heights for the three tips. (A small ~15 by 26 pixel wide margin of the unobscured image is seen in the upper–left-hand corner behind the overlain image). c Crystallographically averaged p4 plane symmetry reconstruction of a 512 by 512 pixel fully obscured portion of this “sample.”