An Application of F ree Form Deformation to Phytoplankton Cells Modeling

In the paper the main stages of the process of 3D phytoplankton model construction based on their digitized images is described. The process of 3D phytoplankton model creation consists of sequential scaling, rotating and fitting of the outline of a base model, which represents a phytoplankton species with average dimensions, to the cell outline on the digitized image. The model fitting is provided by Free Form Deformation (FFD), which is defined by parametric functions whose values are determined by the location of control points. In first case, when dimensions of an organism are given, the distances between control points are equated to the given dimensions. In second case, when a photo of an organism is given, a scientist should: (1) rotate and scale a base model to achieve a visual coincidence of its orientation and dimensions with the orientation and dimensions of species on the digitized photo, and (2) deform the base model by displacing control points of FFD. Our algorithm allows studying morphological changes of microorganisms and describing their shapes by control points coordinates. General Terms Algorithms.