Dans cette thèse, une nouvelle représentation des images couleur basée sur une généralisation du signal analytique est introduite. En utilisant l'analogie entre les conditions de Cauchy-Riemann, qui définissent le caractère holomorphe d'une fonction, et l'équation de Dirac dans l'algèbre de Clifford R_{5,0}, un système d'équations dont la solution est le signal monogène couleur est obtenu. Ce signal est notamment basé sur des noyaux de Riesz ainsi que de Poisson 2D, et une représentation polaire, basée sur un produit géométrique, peut lui être associée. Les applications envisagées reposent majoritairement sur cette représentation polaire et sur les informations de couleur et de structures locales s'y rattachant. Des problématiques liées au flot optique couleur, à la segmentation couleur multi-échelle, au suivi d'objets couleur et à la détection de points d'intérêt sont abordées. En ce qui concerne le flot optique, nous nous intéressons à l'extraction du mouvement d'objets d'une certaine couleur en remplaçant la contrainte de conservation de l'intensité par une contrainte de conservation d'angles. Pour la segmentation, une méthode de détection de contours basée sur de la géométrie différentielle et plus particulièrement sur la première forme fondamentale d'une surface, est proposée afin de déterminer les contours d'objets d'une couleur choisie. Pour le suivi d'objets, nous définissons un nouveau critère de similarité utilisant le produit géométrique que nous insérons dans un filtrage particulaire. Enfin, nous resituons la définition du détecteur de Harris dans le cadre de la géométrie différentielle en faisant le lien entre ce dernier et une version "relaxée" du discriminant du polynôme caractéristique de la première forme fondamentale. Ensuite nous proposons une nouvelle version multi-échelle de ce détecteur en traitant le paramètre d'échelle comme une variable d'une variété de dimension 3. / In this thesis, a novel framework for color image processing is introduced based on the generalization of the analytic signal. Using the analogy between the Cauchy-Riemann conditions and the Dirac equation in the Clifford algebra R_{5,0}, a system of equations which leads to the color monogenic signal is obtained. This latter is based on the Riesz and 2D Poisson kernels, and a polar representation based on the geometric product can be associated to this signal. Some applications using color and local structure information provided by the polar representation are presented. Namely, color optical flow, color segmentation, color object tracking and points of interest are developed. Extraction of optical flow in a chosen color is obtained by replacing the brightness constancy assumption by an angle constancy. Edge detection is based on the first fundamental form from differential geometry in order to segment object in a predefined color. Object tracking application uses a new similarity criterion defined by geometric product of block of vectors. This latter is viewed as the likelyhood measure of a particle filter. Last part of the thesis is devoted to the definition of the Harris detector in the framework of differential geometry and a link between this definition and a relaxed version of the characteristic polynomial discriminant of the first fundamental form is given. In this context, a new scale-space detector is provided as the result of handling the scale parameter as a variable in a 3-manifold.

A dissertation submitted in partial compliance with the requirements for the Master's Degree in Technology: Homoeopathy, Durban University of Technology, 2008. / Conduct a randomised, double blind, placebo controlled study in order to determine the sphere of action of the imponderable remedy Pink 30CH on healthy volunteers who recorded the signs and symptoms produced in order to determine the substances potential usefulness in a future clinical setting according to the Law of Similars. Determine and highlight the commonalities shared between the symptoms and themes produced by remedy Pink 30CH and the other selected imponderable remedies. In the homoeopathic drug proving of remedy Pink 30CH, provers were uninformed to both the nature of the substance as well as to the potency selected and used for proving purposes. Neither the provers nor the research investigator had any knowledge of who received the verum or the placebo until the end of the proving. Thirty (30) provers were selected after meeting the inclusion criteria of which thirty percent (30%) of the subjects received placebo in a randomised fashion. Verum and placebo were dispensed to the proving body in a set of six (6) powders which were taken sublingually three (3) times daily or until any proving symptoms were experienced. All provers were examined and made to record in their journals before, during and after the administration of the proving substance so as to serve as their own intra-individual controls. At the end of the proving period all journals were then recalled and all proving data recorded was then collated and edited into a repertory and materia medica format, which was then used to formulate a homoeopathic drug picture of the remedy that could be used in future clinical settings. The homoeopathic drug picture thus derived was then analysed with the aim of highlighting the important themes that were elicited during the proving. These symptoms and themes were then related and compared to seven (7) other imponderable remedies: Luna (Moonlight); Magnetis Polus Arcticus (North pole of the magnet); Magnetis Polus Australis (South pole of the magnet); Positronium (Anti-matter); Radium bromatum (Radium bromide); Sol (Sunlight) and X-ray, in order to expand the overall understanding of the commonalities shared by the imponderabilia as an entirety. / M

Frying oil is a heat and mass transfer medium, which affects the quality of food. The reaction mechanisms in deep-frying oils are mainly thermal oxidation, hydrolysis, and polymerization, which result in lipid deterioration. Addition of synthetic or natural antioxidants can effectively slow down lipid deterioration during deep-frying. Total polar components, polymerized triglycerides, p-anisidine value, acid value and iodine value are reliable indicators for assessing oil degradation during frying. Color darkening of deep-frying oils is one of apparent changes during deep-frying and is closely associated with the levels of decomposition compounds in the frying oils. However, the evidence of the relationship between color and deep-frying oil quality indicators are scanty. The main objective of this thesis is to develop a model for rapid assessment of oil quality during 30-hour deep-frying processes using oil color and quality as indicators. Significant color changes (p < 0.05) were observed in soybean oil as compared to canola and sunflower oil during 30-hour deep-frying trials. Canolol-enriched frying oils showed the highest color values before deep-frying, but the final results showed the least color changes (p < 0.05) during the 30-hour deep-frying trials. The highest percentage of total polar components (15.55 %), polymeric triglycerides (9.3 %), and p-Anisidine value (62.34) were found in TBHQ-enriched deep-frying oil samples in soybean oil. The highest acid value (3.06 mg KOH/100g) was found in canolol-enriched frying oil samples in canola oil. Rosemary and canolol-enriched deep-frying oil samples showed significant effect (p < 0.05) on color changes while reducing formation of total polar components, polymeric triglycerides, and aldehydes during the 30-hour deep-frying study. Significant correlations (p < 0.05) were found between color and oil quality indicators in all of the deep-frying oil samples; significant regression (p < 0.05) models are expressing the level of oil deterioration from color (light-dark, red-green, yellow-blue) in deep-frying oils. Overall, this study established several models using color as an indicator aiming to rapidly assess deep-frying oil quality. / October 2016

Pollinator-driven selection is thought to drive much of the extraordinary diversity of flowering plants. Plants that produce floral traits preferred by particular pollinators are more likely to receive conspecific pollen and to evolve further adaptations to those pollinators that enhance pollination and ultimately generate floral diversity. Two mechanisms in particular, sensory bias and learning, are thought to explain how pollinator preference can contribute to divergence and speciation in flowering plants. While the preferences of pollinators, such as bees, flies, and birds, are frequently implicated in patterns of floral trait evolution, the role of learning in generating reproductive isolation and trait divergence for different floral types within plant populations is not well understood. Floral color polymorphism in particular provides an excellent opportunity to examine how pollinator behavior and learning might maintain the different floral morphs. In this study we asked if bumble bees showed innate preferences for different color morphs of the pollen-only plant Solanum tridynamum, whether bees formed preferences for the morphs with which they had experience collecting pollen from, and the strength of those learned preferences. Using an absolute conditioning protocol, we gave bees experience collecting pollen from a color polymorphic plant species that offered only pollen rewards. Despite initially-naïve bees showing no apparent innate bias toward human-white versus human-purple flower morphs, we did find evidence of a bias in learning. Specifically, bees learned strong preferences for purple corollas, but learned only weak preferences for hypochromic (human-white) corollas. We discuss how our results might explain patterns of floral display evolution, particularly as they relate to color polymorphisms. Additionally, we propose that the ease with which floral visual traits are learned—i.e., biases in learning—can influence the evolution of floral color as a signal to pollinators.

On the premise that examination of a poet's language can provide a valid and significant approach to the study of a work of art, this thesis proposes to make such a study of Prometheus Unbound, the major poetical work of Percy Bysshe Shelley, with specific attention to his use of color language.

The purpose of this study was to examine (1) whether the Weigl-Goldstein-Scheerer Color Form Test and the Proverbs Test were able to discriminate between a sample of normal patients and a sample of schizophrenic patients, and (2) to determine if there was a significant correlation between these two instruments.

In an industrial hallway, the pipes and garage doors are echoed with a soft, yet plastic skin.Intense filtered sunlight streams through a sheath of fuchsia--we walk beneath it and it washes our faces with color.A monochromatic corridor is transformed by unexpected passages of turquoise, red, and pink. A demure sheetrock wall becomes ethereal and gentle, luring us behind to only find ourselves.The works are celebratory and act as a landscape, tombstone rubbing, line drawing, and uberquilt--all wrapped into one.

Until the 1960s there was more interest in Josef Albers as an artist. Albers' successful teaching career began in 1923 at the Bauhaus where he was eventually placed in charge of the whole elementary course. Albers' American educational career centered around Black Mountain College in North Carolina and Yale University where he was chairman of the Department of Design.This paper, in effect, will deal with Albers as an artist, teacher, and theorist. Albers as an artist will be explored by a study of Homage to the Square, the series from which much of Albers' present fame is derived. Albers' color theory is contained in his writing, Interaction of Color, a book dedicated to his students which records his method of teaching color. It is the purpose of this paper to show Albers' theory and his paintings, Homage to the Square, exemplify many principles of perception: the realization that color experience is a subjective, inward experience, the Gestalt notions on "good" forms, and the awareness that our knowledge is of the perception of things -- not of things themselves. In order to pursue such a course of study, it will be necessary to investigate other color theories, theories of perception, Albers' work and evaluations of his works.

This Thesis presents several approaches through art making to deal with light and space and other things, and the relations that their interaction may generate

Each stitch is a piece of me that I give, a moment of my life and a unit of my love, meticulously culminated into a universal visual language. The optimist in me knits for the cause, while my formalist counterpart works to make the images that sell my thoughts. I knit for the lovers.I make these objects as a practice and a confirmation of my optimism. I make these images to communicate and persuade as a serious contender while at the same time retaining my own optimism and sanity by promising to never take myself too seriously.