Extended Data Fig. 3. Comparison of PSSR vs. BM3D on EM data.

PSSR restoration was compared to the Block-matching and 3D filtering (BM3D) denoising algorithm. BM3D was applied to low-resolution real-world SEM images before (LR-BM3D-Bilinear) and after (LR-Bilinear-BM3D) bilinear upsampling. A wide range of Sigma ($\sigma \in \left(0,\mathrm{ }95\right]$, with step size of 5), the key parameter that defines the assumed zero-mean white Gaussian noise in BM3D method, was thoroughly explored. Images of the same region from the LR input, bilinear upsampled, PSSR restored, and Ground truth is displayed in (a). Results of LR-BM3D-Bilinear (b, top row) and LR-Bilinear-BM3D (b, bottom row) with sigma ranging from [10, 15, … , 35] are shown. PSNR and SSIM results of LR-BM3D-Bilinear and LR-Bilinear-BM3D across the explored range of sigma are plotted in (c) and (d). Metrics for bilinear-upsampled and PSSR-restored images of the same testing set are shown as dashed lines in orange (LR-Bilinear: PSNR=26.28±0.085; SSIM=0.767±0.0031) and blue (LR-PSSR: PSNR=27.21±0.084; SSIM=0.802 ±0.0026). n=12 independent images for all conditions. Values are shown as mean ± SEM.