Fig. 3. Precision and accuracy of the pixel and subpixel cell detection methods.

(A) Variance of cell contour edge localization (14,660 edges from 116 cells, each sampled 301 times in a time-lapse experiment) from cell detection with the pixel and subpixel algorithms. Variance is measured in pixels² (bottom x axis) and nm² (top x axis). (B) Top left, simulated 2D phase-contrast image. The scale bar represents 1 μm. Top right, same but with the true edge location (red). Bottom left, same but with cell contour obtained with the pixel algorithm (blue). Bottom right, same but with cell contour obtained with subpixel algorithm (green). (C) Histogram of distance of cell contour edge localization to true cell edge coordinate (2,348,162 vertices from 22,500 cells). The localization error is measured in pixels (bottom x axis) and nm (top x axis).