Fig. 8. Methods comparison on simple targets: Exposure time for these scenes are all 1000 ms per each pixel measurement.

The total acquisition time for each target is 390 min. The width of the reconstruction cube size in each dimension is about 2 m as given along with other reconstruction parameters in Supplementary Table 4. Each row shows a different simple target, each column the reconstruction from different methods. The first column stands for our proposed RSD based solver with one spatial section (inside white circle) corresponding to Eq. (13). The second column is from Direct Integration (back-projection solver) for comparison with the first column. The last two columns show the approximate method⁹ which approximate non-confocal as a confocal datasets and reconstruct through confocal solvers (LCT: forth column, FK-migration: fifth column). For the last two columns, each small image shows the results from midpoint approximation⁹ in order to approximate confocal data from non-confocal measurements. The respective larger image results from zero-padding applied to the input data to show the same reconstruction volume as the first three columns.