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Presentation Information     2005-11-21 (15:15)   •  The seminar room at Vi2

Speaker Natasa Sladoje
Comment Pre-dissertation talk
Title On Analysis of Discrete Spatial Fuzzy Sets in 2 and 3 Dimensions
Abstract I will give a brief overview of the results presented in my PhD thesis. A general goal for the research has been to develop shape analysis methods that can be applied to fuzzy segmented images in 2D and 3D. We have studied representation and reconstruction of a shape by using moments of both its crisp and fuzzy discretization.

We show, both theoretically and statistically, that the precision of estimation of moments of a shape is increased if a fuzzy representation of a shape is used, instead of a crisp one. The signature of a shape based on the distance from the shape centroid is studied and two approaches for its calculation for fuzzy shapes are proposed. A comparison of the performance of fuzzy and crisp approaches is carried out through a statistical study, where a higher precision of shape signature estimation is observed for the fuzzy approaches. The measurements of area, perimeter, and compactness, as well as of volume, surface area, and sphericity, are considered, too. New methods are developed for the estimation of perimeter and surface area of a discrete fuzzy shape. It is shown through statistical studies that the precision of all the observed estimates increases if a fuzzy representation is used and that the improvement is more significant at low spatial resolutions. In addition, a defuzzification method based on feature invariance is designed, utilizing the improved estimates of shape characteristics from fuzzy sets to generate crisp discrete shapes with the most similar shape characteristics.