Fig. 3

a Schematic of an artificial NN to recognize pores of the diatoms (NN 2). b Frame of an original diatom image that is loaded into the NN 2. c Pixel-wise classification map of the NN 2 corresponding to raw image (b). d Result of the application of the NN 2 to the image of a diatom (red circles are recognized pores); scale bar is 300 nm