In the original paper,1 Figure 1(c) incorrectly displays the units for the x and y axes as nm instead of μm. The correct Figure 1 is shown.

FIG. 1.

Graphical representations of 3D particle tracking via 2D normalized cross-correlation for a 2 μm bead. (a) In-focus or “current” image (70 pixels × 70 pixels) of a 2 μm-diameter bead. (b) Out-of-focus “template” image (50 pixels × 50 pixels) of a 2 μm-diameter bead. (c) The NCC surface, corresponding to the “current” and “template” images shown in (a) and (b). (d) The MCC as a function of the stuck bead’s axial position. We step up the piezo-electric translation stage in 100 nm increments and calculate the maximum of the NCC surface between an image at each step and the fixed “template” image located at the vertical red dotted line (shown in (b)). The vertical green dotted line indicates an ideal position at which to stabilize the bead’s current position (the “current” image shown in (a)).

FIG. 1.

Graphical representations of 3D particle tracking via 2D normalized cross-correlation for a 2 μm bead. (a) In-focus or “current” image (70 pixels × 70 pixels) of a 2 μm-diameter bead. (b) Out-of-focus “template” image (50 pixels × 50 pixels) of a 2 μm-diameter bead. (c) The NCC surface, corresponding to the “current” and “template” images shown in (a) and (b). (d) The MCC as a function of the stuck bead’s axial position. We step up the piezo-electric translation stage in 100 nm increments and calculate the maximum of the NCC surface between an image at each step and the fixed “template” image located at the vertical red dotted line (shown in (b)). The vertical green dotted line indicates an ideal position at which to stabilize the bead’s current position (the “current” image shown in (a)).

Close modal
1.
P. K.
Koo
,
S. U.
Setru
, and
S. G. J.
Mochrie
,
Rev. Sci. Instrum.
84
,
103705
(
2013
).