Fig. 3. Denoising with the general model in Topaz enhances SNR of short exposure micrographs.

a SNR (dB) calculated using the split-frames method (see Methods) as a function of electron dose in low-pass filtered micrographs by a binning factor of 16 (blue), affine denoised micrographs (orange), and U-net denoised micrographs (green) in the four NYSBC K2 datasets. Our U-net denoising model enhances the SNR of micrographs across almost all dosages in all four datasets. U-net denoising enhances SNR by a factor of 1.5× or more over low-pass filtering at 20 e-/A². b Example section of a micrograph from the 19jan04d dataset of apoferritin, β-galactosidase, a VLP, and TMV (full micrograph in Supplementary Figs. 3 and 4) showing the raw micrograph, low-pass filtered micrograph, affine denoised micrograph, and U-net denoised micrograph over increasing dose. Particles are clearly visible at the lowest dose in the denoised micrograph and background noise is substantially reduced by Topaz denoising.