Dual-View Selective Instance Segmentation Network for Unstained Live Adherent Cells in Differential Interference Contrast Images

The cell, the fundamental unit of life, is a complex of material metabolism, energy conversion, and information regulation. For a typical cell, whether a bacterial or an animal cell, water accounts for about 70% of its weight, which causes it transparent [1]. Consequently, when such a cell is observed under a bright-field microscope, the contrast is very weak, leading to poor image quality. So, it is best to use a phase contrast microscope or a differential interference contrast (DIC) microscope to observe live cells. The former, a phase contrast microscope, reveals more detail of a cell's internal structures and discerns its attachments to nearby cells. While the latter, a DIC microscope, provides pseudo-three-dimensional images with a shadow-cast appearance. In addition to these two imaging modes, fluorescence microscopy is a commonly used approach for observing specific macromolecules, such as proteins and nucleic acids in cells in modern biological laboratories [2]. In a fluorescence microscope, a short-wavelength excitation light passing through the excitation filter irradiates the fluorescent molecules (fluorophores) marked in the sample to generate visible light of a particular wavelength that can be seen by the viewer or digitally captured using a complementary metal oxide semiconductor (CMOS) or charge-coupled device (CCD).