Robust cell segmentation for schizosaccharomyces pombe images with focus gradient

Schizosaccharomyces pombe shares many genes and proteins with humans and is a good model for chromosome behavior and DNA dynamics, which can be analyzed by visualizing the behavior of fluorescently tagged proteins in vivo. Performing a genome-wide screen for changes in such proteins requires developing methods that automate analysis of multiple images, the first step of which requires robust segmentation of the cell. We developed a segmentation system, PombeX, that can segment cells from transmitted illumination images with focus gradient and varying contrast. Corrections for focus gradient are applied to the image to accurately detect cell membrane and cytoplasm pixels. Quantitative evaluations show overall good segmentation performance on a large set of images, regardless of different image quality, lighting condition, focus condition and phenotypic profile. Comparisons with recent related methods show that PombeX outperforms current methods for fission yeast cell image segmentation.