Abstract: "The topic of this thesis is segmentation of grey-scale images by accessing and relating the structures of the image for all reasonable scales. Grey-scale images are regarded as physical measurements obtained by an ensemble of detectors with finite aperture and finite readout precisio...

Ausführliche Beschreibung

Bibliographische Detailangaben

1. Verfasser:	Olsen, Ole Fogh (VerfasserIn)
Format:	Buch
Sprache:	English
Veröffentlicht:	København 1996
Schriftenreihe:	Datalogisk Institut <København>: DIKU-Rapport 1996,30
Schlagworte:	Computer graphics Computer vision Gaussian processes Image processing
Zusammenfassung:	Abstract: "The topic of this thesis is segmentation of grey-scale images by accessing and relating the structures of the image for all reasonable scales. Grey-scale images are regarded as physical measurements obtained by an ensemble of detectors with finite aperture and finite readout precision. Based on this point of view, the notion of image is established using linear Gaussian scale space and Morse theory. The problem of segmentation is addressed within the framework of linear Guassian scale space. The image at a given scale is partitioned according to a dissimilarity measure. Each minimum in the measure corresponds to exactly one segment. The segment is defined as the catchment basin belonging to the minimum. The gradient squared is used as the measure of dissimilarity. An essential part of the scale-space paradigm is to study the family of images indexed by scale as a family and not as a distinct set of images The structure of the segments across scale are analysed exploiting the established duality between the minima in the dissimilarity measure and the segments. Catastrophe theory is used to analyse the structure of the minima across scale. The generic catastrophe events for the minima of the gradient squared are proved to be the fold and the cusp catastrophes. The generic events of annihilation, creation, split and merge for the minima are used to analyse possible linking schemes for the segments. The implemented linking scheme produces a hierarchical structure. Two segments are merged when the saddle connecting the two corresponding minima is annihilated. A segment is divided when a border is created within the segment. The creation of a border corresponds to the creation of a saddle connecting the resulting two minima. The duality between minima and catchment basins is exploited to make a robust implementation of the linking scheme The actual detection and tracking of segments is region based. A semi-automatic segmentation tool based on this uncommitted segmentation scheme has been implemented. Experimental results obtained using the segmentation tools on artificial, camera and medical data are presented. The experimental data are two and three dimensional. The singularity analysis and the implementation is performed for two and three dimensional images. The theory can be generalised to arbitrary finite dimension. This thesis also includes an introduction to scale-space theory, differential invariants, differential description of local forms for two and three dimensional functions, single scale and multi-scale segmentation methods, Morse theory and Catastrophe theory [sic].
Beschreibung:	88 S.