Fig. 2

Virtual-imaging-assisted AO enables aberration correction for dense 2 μm fluorescent beads. a Shifted images acquired under zonal illumination and image acquired under full-pupil illumination. The entire wavefront is split into an array of segments (red dashed squares), and the acquired shifted images are arranged by the corresponding wavefront segment. The image marked by the cyan square was acquired under full-pupil illumination with the same FOV as the shifted images, and it was used as the reference image in the conventional method. b Maximum intensity projection of the captured image volume, which serves as the sample in virtual imaging. The yellow dashed box in the lateral view marks the imaging FOV during zonal illumination. The yellow dashed line in the axial view indicates the objective focal plane during the aberration measurement process. c Maps of structural similarity with respect to the shift. In each map, the shift with the largest similarity is marked by the red dot. d Shifted image, reference image and similarity map for a representative wavefront segment marked by the yellow asterisks in (a) and (c). The red box indicates the patch of the reference image exhibiting the largest similarity with the shifted image. e Maximum intensity projection of the image volume without AO correction (No AO), with AO correction using the conventional method (Conv) and our method (AO), and under the initial condition where no artificial aberration is applied (Init). The insets in the images without AO correction and with AO correction using the conventional method are digitally enhanced 3-fold and 8-fold, respectively, to increase the visibility. f Corrective wavefront. The dashed squares indicate the layout of the wavefront segments, where each wavefront segment corresponds to a unit square. An independent mask approach was used in the measurement process. g Signal profiles along the cyan, brown, magenta and orange lines in e. Scale bars, 5 μm