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A realistic visualization that enhances a virtually authentic experience is the ambition of any visualization system in a simulator environment. But calibrating and maintaining a high quality visualization system entail large costs, resources and time. Hence, a soft- ware has been developed to facilitate the measuring of three useful metrics that lay the foundation for automatic calibration of visual projector systems. The software and associ- ated method conducts relevant measurements which are compatible with arbitrary surface shapes and can be utilized as an assurance of quality measurement tool. The measure- ments include absolute surface shape, absolute geometry and projector blending zone con- tributions. The implementation decrease manual complexity for users, adds environmen- tal flexibility, increase density of measurement points and is more cost and time efficient then existing methods. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

The design of industrial products applies various construction aspects. Beside functionality and manufacturability conditions that are essential in technical design, products must also meet aerodynamic, hydrodynamic and aesthetic demands. These demands are particularly important in automotive, ship and airplane industry but they are also present in the design of medical replacements, household appliances, etc. The common objective of above aspects is to produce smooth and irregularity free surface shape. Quality and smoothness of surfaces of industrial objects can efficiently be evaluated by highlight lines.

The design of industrial products applies various construction aspects. Beside functionality and manufacturability conditions that are essential in technical design, products must also meet aerodynamic, hydrodynamic and aesthetic demands. These demands are particularly important in automotive, ship and airplane industry but they are also present in the design of medical replacements, household appliances, etc. The common objective of above aspects is to produce smooth and irregularity free surface shape. Quality and smoothness of surfaces of industrial objects can efficiently be evaluated by highlight lines.

Temperature drifts, tool deterioration, unknown vibrations as well as spindle play are major effects which decrease the achievable precision of computerized numerically controlled (CNC) lathes and lead to shape deviations between the processed work pieces. Since currently no measurement system exist for fast, precise and insitu 3d shape monitoring with keyhole access, much effort has to be made to simulate and compensate these effects. Therefore we introduce an optical interferometric sensor for absolute 3d shape measurements, which was integrated into a working lathe. According to the spindle rotational speed, a measurement rate of 2,500 Hz was achieved. In-situ absolute shape, surface profile and vibration measurements are presented. While thermal drifts of the sensor led to errors of several µm for the absolute shape, reference measurements with a coordinate machine show, that the surface profile could be measured with an uncertainty below one micron. Additionally, the spindle play of 0.8 µm was measured with the sensor.

La complexité de la forme de la surface est une caractéristique morphologique des surfaces pliées. Dans cette thèse, nous visons à développer des méthodes spectrales pour quantifier cette caractéristique du cortex cérébral humain reconstruit à partir d'images MR structurales. Tout d'abord, nous suggérons certaines propriétés qu'une mesure standard de la complexité de surface devrait posséder. Ensuite, nous proposons deux définitions claires de la complexité de la surface en fonction des propriétés de flexion de surface. Pour quantifier ces définitions, nous avons étendu la transformée de Fourier à fenêtres illustrée récemment pour transformer en maillage des surfaces. Grâce à certaines expériences sur les surfaces synthétiques, nous montrons que nos mesures basées sur la courbure permettent de surmonter les surfaces classiques basées sur la surface, ce qui ne distingue pas les plis profonds des oscillants ayant une surface égale. La méthode proposée est appliquée à une base de données de 124 sujets adultes en bonne santé. Nous définissons également la complexité de la surface par la régularité de Hölder des mouvements browniens fractionnés définis sur les collecteurs. Ensuite, pour la première fois, nous développons un algorithme de régression spectrale pour quantifier la régularité de Hölder d'une surface brownienne fractionnée donnée en estimant son paramètre Hurst H. La méthode proposée est évaluée sur un ensemble de sphères browniennes fractionnées simulées. En outre, en supposant que le cortex cérébral est une surface brownienne fractionnée, l'algorithme proposé est appliqué pour estimer les paramètres Hurst d'un ensemble de 14 corticus cérébraux fœtaux. / Surface shape complexity is a morphological characteristic of folded surfaces. In this thesis, we aim at developing some spectral methods to quantify this feature of the human cerebral cortex reconstructed from structural MR images. First, we suggest some properties that a standard measure of surface complexity should possess. Then, we propose two clear definitions of surface complexity based on surface bending properties. To quantify these definitions, we extended the recently introduced graph windowed Fourier transform to mesh model of surfaces. Through some experiments on synthetic surfaces, we show that our curvature-based measurements overcome the classic surface area-based ones which may not distinguish deep folds from oscillating ones with equal area. The proposed method is applied to a database of 124 healthy adult subjects. We also define the surface complexity by the Hölder regularity of fractional Brownian motions defined on manifolds. Then, for the first time, we develop a spectral-regression algorithm to quantify the Hölder regularity of a given fractional Brownian surface by estimating its Hurst parameter H. The proposed method is evaluated on a set of simulated fractional Brownian spheres. Moreover, assuming the cerebral cortex is a fractional Brownian surface, the proposed algorithm is applied to estimate the Hurst parameters of a set of 14 fetal cerebral cortices.