El color y la textura son dos estímulos visuales importantes para la interpretación de las imágenes. La definición de descriptores computacionales que combinan estas dos características es aún un problema abierto. La dificultad se deriva esencialmente de la propia naturaleza de ambas, mientras que la textura es una propiedad de una región, el color es una propiedad de un punto.Hasta ahora se han utilizado tres los tipos de aproximaciones para la combinación, (a) se describe la textura directamente en cada uno de los canales color, (b) se describen textura y color por separado y se combinan al final, y (c) la combinación se realiza con técnicas de aprendizaje automático. Considerando que este problema se resuelve en el sistema visual humano en niveles muy tempranos, en esta tesis se propone estudiar el problema a partir de la implementación directa de una teoría perceptual, la teoría de los textons, y explorar así su extensión a color.Puesto que la teoría de los textons se basa en la descripción de la textura a partir de las densidades de los atributos locales, esto se adapta perfectamente al marco de trabajo de los descriptores holísticos (bag-of-words). Se han estudiado diversos descriptores basados en diferentes espacios de textons, y diferentes representaciones de las imágenes. Asimismo se ha estudiado la viabilidad de estos descriptores en una representación conceptual de nivel intermedio.Los descriptores propuestos han demostrado ser muy eficientes en aplicaciones de recuperación y clasificación de imágenes, presentando ventajas en la generación de vocabularios. Los vocabularios se obtienen cuantificando directamente espacios de baja dimensión y la perceptualidad de estos espacios permite asociar semántica de bajo nivel a las palabras visuales. El estudio de los resultados permite concluir que si bien la aproximación holística es muy eficiente, la introducción de co-ocurrencia espacial de las propiedades de forma y color de los blobs de la imagen es un elemento clave para su combinación, hecho que no contradice las evidencias en percepción. / Colour and texture are important visual cues for image understanding. The definition of computational descriptors that combine both features is still an open problem. The difficulty is essentially due to the inherent nature of both cues, while texture is a property of a region, colour is a property of a point.Since now three approaches have been used for combining cues, (a) texture is directly described in each one of the colour channels, (b) texture and colour are described separately and combined in a latter step, and (c) the combination is done using machine learning techniques. Considering that this issue is solved at early stages of the human visual system, in this work we propose to study the problem using a direct implementation of a perceptual theory, the texton theory, and to explore its extension to colour.Since texton theory is based on the description of texture by the densities of local attributes, this matches perfectly with an holistic framework where descriptors are based on bag-of-words. Some descriptors based on different textons spaces and different image representations have been studied. Furthermore, the feasibility of these descriptors has also been studied for intermediate levels of image representation.The proposed descriptors have proved high efficiency in retrieval and image classification. They also present some advantages in vocabulary generation. The quantification is done directly on low-dimensional spaces, whose perceptual properties allow low-level semantic associations to the visual words. The results make us to conclude that although the performance of holistic approaches is high, the introduction of spatial co-ocurrence of blob properties, shape and colour, is a key element for their combination. This conclusion agrees with perceptual evidences.

Character design is applied widely both in the game and movie industry. For character designers, it is essential to design intuitively and to avoid repeated and unfulfilling designs. To understand certain methodologies used in design, this degree project investigates if there are further limitations or considerations that need more attention when designing purposeful characters. To get an overview if culture, age and gender affect the choice of shapes and colour schemes of characters, as a method, the online survey was used providing results based on answers from 72 participants.

The Houston Constellation is a type of architectural urbanism situated at the intersection of urban revision and projections for cultures yet unknown. The intent is to provide a template for refiguring new lines of sight and interaction within the contemporary city, between contingent forces, institutions, and a public in flux. The Houston Superdistrict: a heterogeneous collection of 20th Century urban paradigms packed loosely underneath a thick canopy. Institutions in medicine, the arts, education, and recreation make it a major hub for local and global populations. The area is undergoing a transformation, yet in contrast to its ambitious visions, current plans project investment that may drop more single objects into this static field. This project proposes an alternative. A constellation of form that slides across cold boundaries and catalyzes a new spatial consciousness to produce a newly legible environment. Encouraging creativity- the very hope for the district in the first place- begins with architectural performance and contextual interaction. Techniques and tactics of planametric alignment, visual continuity, and material cohesion provide the system a relational fitness, while establishing a larger counterform against context’s existing linear boulevards, axes, and grids. Four forms (R,G,B,O) based on site-specific conditions, constitute programmatic points with distinct characters. A complementary duality, the figures in the park (O & B) engage the spatial and airy quality of the city. While the institutional figures (R & G) embed themselves within the local form of their respective campuses. Producing new linkages between fabric and institution: the Museum of Fine Arts Houston and Rice University link through a new space for the arts in the public realm. Hermann Park’s City Beautiful design is reawoken with a new spine and periphery.

This thesis work has introduced process orientation at the printing company Color Print Sweden AB. The outcome ofthis work is a survey of the work flow at the prepress department. To visualise the production process at the companya comprehensive mapping of the main process, order-to-delivery, has been made. The work has detected a couple ofcritical elements in the existing process. These elements are the following: initial check of material delivered to the prepressdepartment as well as the control made of the plotter print-out, digital test print and plate. To guarantee the qualityof the prints it is very important that the work made in the prepress department is optimized. This survey can thereforebe used as a basis for continuous improvement in the processes at Color Print Sweden AB. This work has alsoresulted in a template that Color Print Sweden AB can use to design routine descriptions to ensure that specific worktasks are performed the right way by everyone and all the time.

Introduction Nearly all flat panel video display monitors have luminance and colour variations as the angle of view varies from the monitor’s perpendicular. The new MicrotileTM displays developed by Christie Digital are no exception to this general finding. A review of any book on colour science will show that there is substantial amount of literature on just noticeable colour differences within various colour spaces. Despite the wealth of data on the topic, there is no general consensus across different industries as to which colour space and colour difference equations are appropriate. Several factors like the background colour, object size, texture of the stimulus are different for different studies; these factors make it very difficult to determine precisely the effect of viewing angle on the perception of coloured images on the Microtiles display based on previous research. Hence, the objective of this thesis was to quantify the measured colour shifts of a Microtile display at different viewing angles, in steps of perceptible thresholds and to evaluate the acceptability of distortions at different viewing angles for complex scenes. Methods A preliminary experiment was setup to study the behaviour of Microtile display primaries as a function of viewing angle. The aim was to measure the shift in hue and luminance of the three primaries at different eccentricities (from 0o to 40o). The measured trend was used to simulate Microtile shifts on complex images for the rating task. In the first part of the perceptibility experiment, three reference colours were picked and 12 vectors heading towards the blue-yellow region of the L*a*b* colour space (pertaining to the colour shifts noticed with the Microtile displays). A uniform reference colour was presented in three of the four quadrants on the CRT monitor and one quadrant changed colour in the direction of the sampled vector. An adaptive, four alternate forced choice procedure was employed to determine thresholds for each of the 3 reference colours. The adaptive technique used was a ZEST paradigm. In the second part of the perceptibility experiment, eighteen directions were sampled around each reference colour. The rating task was based on simulating the measured attenuations of the Microtile primaries on complex scenes. Subjects rated the images both in terms of acceptability/unacceptability and as percentage image degradation. The simulation was presented on three static complex images, car, landscape and portrait. A total of 60 subjects participated in the study, 20 subjects for each experiment. All subjects were between the age group of 15 to 35 years of age and underwent battery of colour vision tests before being included in the study. All subjects included had average to superior colour discrimination as categorized using the FM-100 Hue discrimination test. Results Study1: The preliminary study on Microtile display characteristics as a function of viewing angle showed that all the three primaries decreased in luminance with change in viewing angle. The red primary decreased at a faster rate compared to the other two primaries. The trend presents as a decrease in luminance with the hue shifting towards the blue-green region of the CIE1974 L*a*b* space. Study 2: Results from both the first and second parts of the perceptibility experiment showed that the vectors sampled in different directions approximated to ellipsoids in the L*a*b* colour space. This finding was consistent with the colour discrimination literature. Vectors on the equi-luminance plane were significantly longer than the vectors on the non equi-Luminance plane. Results showed that the average perceptibility thresholds in the non equi-luminance direction were lower than 1∆ELab¬¬¬¬. Study 3: Results from the rating experiments showed that irrespective of the complexities in the images, distortions greater than five times thresholds were less than 50% acceptable and were rated to be at least 30% degraded. This corresponds to a viewing angle greater than 10o for a Microtile display. The relationship between the stimulus (ΔE) and subjective Image degradation judgements followed a linear relationship, with the portrait and landscape having similar functions, whereas the car was rated more degraded at lower ΔEs and less degraded at higher ΔEs compared with the other two scenes. Conclusion Perceptibility thresholds for different reference colours showed that the conventionally used calibration precision of 1 ΔELab is a lenient criterion. Perceptibility thresholds are at least 25% less for the Microtile display reference condition. From the results of the rating data a distortion greater than five times thresholds is less than 50% acceptable and appears to be at least 30% degraded for static complex images. However, the image quality judgments appear to be related to scene context, which requires further study.

The development of machine vision algorithms for inspection and machine guidance has traditionally relied on the knowledge and experience of the developers as most of the techniques are based on heuristics and trial and error. This is especially problematic in the area of natural products where variability of the products is the rule rather than the exception. Humans are particularly good in functioning in this arena and in this thesis we look at the development of techniques derived from the functions of the human visual system (HVS). We first identify the significant processes in the HVS and highlight those that we believe are germane to the problems of interest. We then develop computational techniques using these methods and demonstrate their applicability to practical problems. This thesis uses the knowledge that the HVS is considered to consist of three sequential operations (sensing; encoding/transfer; and image interpretation) as a basis for developing a parallel procedure for a machine vision system. We have found that outputs derived from a simulation of the behaviors of receptive fields in the retina and in the higher levels of the brain can generate useful and robust features. Equivalent processes are then developed for machine applications under the guidance of a human operator to identify the areas of interest in the scene for the problem under consideration. Specifically we use the processes for encoding/transfer of data from the retina to develop techniques to enhance color contrasts, and compute color image features that are useful for defect detection and identification in real world images. This is accomplished by a transformation from image space to a characteristic response space that improves the robustness of classification. In this thesis the approach developed is applied to two industrial problems in the quality monitoring of meat and vegetables. The first problem concerns the quality monitoring of breast butterflies and the other the detection of defects on the surface of citrus. The approach is shown to derive algorithms that are robust and can be implemented at high rates of speed. Additionally we also identify a model within which further developments can be conducted as we learn more about the functioning of the HVS.

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Video and industry data were used to assess the inter-relationships of aggression, delivery, coat color, year of birth, number of outs, buckoff percent and score in rodeo bulls. An evaluation of laterality based on observations of how the individual animals were loaded into chutes at 11 bull riding events showed 63% left-handed delivery and 37% right-handed delivery across all observations (n = 525). There was a similar distribution for aggressiveness (based on whether or not the bull charged after the rider dismounted) with 64% of bulls being non-aggressive and 36% of bulls being aggressive. Significant linear relationships existed between score and number of outs and score and buckoff percentage indicating that experience impacted performance. The correlation between number of outs and buckoff percentage was low to moderate (0.06 to 0.30), depending upon the subset of data evaluated. The r-square value for the analysis of score among all bulls was 0.14; however, the r-square value in the subset of bulls with known sires with more than one son was 0.68 when sire was included in the model. Similar increases in r-square values were observed for 2006 average score, career average score, buckoff percentage, and career buckoff percentage, indicating important genetic influences on these traits and/or their component traits. Investigations into the relationship between performance and aggression may help bucking stock producers improve the selection criteria they use. The current trend within the industry is for several breeders to breed ‘hot’ or flighty, nervous cattle to achieve higher performing offspring. Given that there was no association between aggression and score based on chi-square test, aggression may be removed from the criteria for using certain animals for breeding purposes. Based on results from this work, if bucking stock breeders want to make genetic changes in these traits, documentation of pedigree information is vital.

Rainwater harvesting (RWH) is a method of capturing rainfall from a catchment surface and storing it for later use. Though it has been around for thousands of years, its popularity and use has been increasing in recent years and water quality within RWH systems has become a concern. Water temperature is a parameter of water quality and storage container color and shading affect this temperature. Four different colors and three different shadings were applied to twelve rainwater storage barrels. Water temperature of these barrels was measured over twenty weeks during a Texas summer. During the initial ANOVA model, it was determined that the color and shade variables had an interaction and thus both together had an effect on the water temperature. Though the individual treatment variables could not be analyzed and compared statistically, the trends showed that light colors and higher shading caused lower water temperatures in the storage containers. Also, the color had more pronounced effect than shading on water temperature inside the barrels.

No description available.