Fig. 4.

Cropped images of USAF resolution target back-illuminated by a green LED, with fiber shifting motion performed using a translation stage. Large images show Group (G) 7, Elements (E) 3–6, and all elements of Group 8 and 9. Smaller zoomed images show G7,E6, a 2-D plot of the intensities of pixels along the line segment shown by a white line on G7,E6, and the numerical ‘8’. (a) Image acquired with the LS-CLE system and 1.92X GRIN lens (no fiber bundle). (b) Raw experimental LR input image acquired with a fiber bundle and 1.92X GRIN lens. (c–e) Image reconstructed by (c) Gaussian smoothing (σ = 1.7 pixels), (d) Gaussian smoothing with pre histogram equalization and (e) DT algorithm on a single LR image. The respective SR images reconstructed using the proposed method are shown for (f) a 1-D shift pattern where 2 images are acquired with shift of 2.24 µm, (g) a 2-D shift pattern where 4 images are acquired in a square pattern with a shift of 2.24 µm, and (h) a 2-D shift pattern where 8 images are acquired with a 1.12 µm inter-image shift. (i) Single un-cropped image representing all elements of groups 6–9 of USAF target reconstructed using the DT algorithm and 2×2 pattern. Full field of view of each acquired image (in white circle) is 350 µm. Region of interest (marked in red) corresponds to image (g). The scale bar is 10 µm.