Fig. 4.

Comparisons of (a) SNR in dB, (b) fluence mean values before and after denoising at various photon numbers and domains, and (c) SNR improvement after ANLM filtering at ${10}^8$ photons. In (a), both the GPU-ANLM filter (dotted) and a CPU-BM4D³⁵ (dashed) are tested in a homogeneous domain (B1). In (b), three benchmarks (B1—homogeneous, B2—absorbing inclusion, and B3—refractive inclusion) are processed; light and dark shaded regions represent one standard deviation from the mean before and after filtering, respectively. A Gaussian filter is applied to B3 and the cross section is shown in black dashed line. A zoom-in view of the inclusion edge in B3 is shown in the inset. All plots are extracted from the vertical line at $x=50\mathrm{mm}$ and $y=50\mathrm{mm}$ after running 1000 repeated simulations.