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Title Estimation of fat layer thickness profiles in carcass midsections
Author Skytte, Jacob Lercke (Image Analysis and Computer Graphics, Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Supervisor Ersbøll, Bjarne Kjær (DTU Data Analysis, Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2010
Abstract This thesis describes a method for automatically extracting fat layer thickness profiles from CT scanned pig carcass midsections. A fat layer thickness profile can be constructed as shortest distance correspondences between the outlines of skin and muscle, both of which can be segmented out separately. The image data is preprocessed before further use. A virtual tripartition is carried out in order to isolate the carcass midsection. Irrelevant voxels and objects are removed using connected component analysis. Further voxel anomalies are found and repaired using blob detection and a simple reconstruction scheme. Segmentation of the skin outline is carried out using an ad hoc method, which utilizes mathematical morphology, edge tracing, and polar transformation. The muscle outline is segmented out, by trying the following three-dimensional classification schemes: anisotropic diffusion, 3D contextual Bayesian classification, and Markov random field segmentation. These methods are also held up against a two-dimensional classification method, in order to compare the stability towards noise in this type of image data. The intensity range for skin and muscle voxels overlaps, and therefore skin is included in the final muscle classification. This skin is afterwards removed using the, already, segmented skin outline along with distance maps. As the segmented outlines reside in the discrete domain, a guided smoothing is applied using active contours. Thus, a more biological behaviour is obtained as well as sub-voxel accuracy. From the smooth outlines, the final fat layer thickness profiles are created. Finally potential applications, for the fat layer thickness profiles, are presented in both theory and practice. Due to the lack of ground truth, all results are subject to evaluation by visual inspection, which reveals overall good results for the provided image data.
Imprint Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Series IMM-M.Sc.-2010-32
Fulltext
Original PDF ep10_32.pdf (6.72 MB)
Admin Creation date: 2010-06-03    Update date: 2010-12-16    Source: dtu    ID: 262939    Original MXD