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Date of Award

Spring 1994


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Document Type

Thesis: EWU Only

Degree Name

Master of Science (MS) in Computer Science


Computer Science


One of the most important motivations behind computer graphics research is the generation and display of models. A particular area of research in modeling has developed in recent years involving the use of three dimensional images such as those created by Magnetic Resonance Imaging (MRI), and Computed Tomography (CT). An MRI or CT image presents data in the form of a three dimensional array of cubic elements called voxels. The array is created from individual slabs which have often been treated as two dimensional images. The development of segmentation and modeling methods which treat the images as truly three dimensional has relieved people from the task of trying to interpret three dimensional forms from two dimensional images. This thesis presents a new method for segmentation which facilitates the creation of topologically closed polygonal models of arbitrary complexity. The method, called cellular modeling, creates a non-polygonal model which behaves in a manner similar to an expanding soap bubble. The model is composed of uniform, identical elements called cells which replicate themselves in space, causing the model to grow. As the model comes in contact with possible features in an image, cells from the model remain in contact with the features, like a sticky film, while the rest of the model continues to grow. When modeling stops, the outer faces of the cells form a topologically closed boundary that may be transformed into a polygonal solid.