Figure 3.

Computational segmentation and fitting can determine the geometry of ellipsoidal spores. (a) Fluorescence images of B. subtilis are approximately located by a circle-finding algorithm (blue circles) and assigned a number for indexing. (b) Each candidate image is used to fit the parameters of an ellipsoidal image model, with the shell outline and center shown in red over the gray image data. (c) The pixel values in a typical image of B. megaterium can be effectively fitted by the ellipsoidal model.