Fig. 4

Comparative experiments on super-resolution results of a HeLa cell sample with DAPI-labeled nucleus and FITC-labeled \(\alpha\)-SMA at different SNRs. a Comparison of the wide-field image and the super-resolution image obtained by PCA-SIM. The wide-field image is displayed in the upper right triangle, which was obtained by averaging 9 raw SIM images (with the resolution of \(1024 \times 1024\)) captured through a 60\(\times\) objective (\({\textbf {UPlanXApo 60}}\times /{\textbf {1.42 Oil}}\), Olympus, Japan). The super-resolution image reconstructed by PCA-SIM is shown on the bottom left. We show the \(\alpha\)-SMA and nucleus in green and blue, respectively, where the \(\alpha\)-SMA are excited at 488 nm wavelength, and the nucleus at 405 nm wavelength. b Magnified wide-field image (top) and super-resolution images from the boxed regions in a obtained by COR and PCA-SIM. c, d Magnified wide-field images (top) and super-resolution images from the yellow boxed regions in a obtained by COR and PCA-SIM under different noise environments. e The wide-field images under different noise environments (since wide-field images are obtained by multi-frame averaging, the quality of raw SIM images with noises is actually worse, and when the noise power reaches 70 dBW, the sample signals are almost completely drowned). f Structural similarity indexes of the super-resolution results of COR and PCA-SIM under different SNRs with respect to b, respectively. Experiments were repeated thirty times independently with similar results. Colored arrows point to regions where reconstruction differences are distinct. Scale bars: 10 \(\mu\)m (a), (e) ; 1 \(\mu\)m (b)-(d)