This research explores the differences between how game engine cameras and the human visual system (HVS) render colour. The study is motivated by a two part research question: will HVS colours or game camera colours be preferred when experiencing a virtual environment from a 1st-person perspective and how does light intensity relate to preference? While previous research defines perceptual processes which influence the interpretation of colour information this study advances the understanding of how these theories may be applied to 3D colour grading.When evaluating the two colour modes with a combination of quantitative data and qualitative reflections it was possible to establish a correlation between preference and light intensity, in the sense that HVS colours were preferred in high illumination and camera colours in low. The findings implicate that in order to be well received the colours of a virtual environment need to be adjusted according to illumination.

<p>The aim of this thesis is to develop an technical aid (software) to help people with colourblindness. Colour blind people have difficulties to differentiate between certain colours,so the implemented software will name a selected colour. The software is implementedas a Mozilla Firefox extension and also uses a XPCOM component. Furthermore canthe user select different colour databases and change the displaying properties.The aim of this thesis is to develop an technical aid (software) to help people with colourblindness. Colour blind people have difficulties to differentiate between certain colours,so the implemented software will name a selected colour. The software is implementedas a Mozilla Firefox extension and also uses a XPCOM component. Furthermore canthe user select different colour databases and change the displaying properties.</p>

Abstract Production of pulp and paper from raw wood involves the washing of substantial quantities of highly coloured material from the wood pulp. Although most of this colour is trapped within the mill and the mills wastewater treatment system, discharge of coloured wastewater remains a problem of public concern. Lake Rotorua, New Zealand is filled with sediment consisting almost exclusively of diatoms. The most abundant species, Aulacoseira, has been shown to have very small pores, less than 200 nm, that could be very useful for the capture and holding of large organic molecules. Lake Rotorua is situated close to the two largest pulp and paper mills in New Zealand and may have to be dredged to solve a problem of eutrophication. Wastewaters generated at the Kinleith (Tokoroa) and Tasman (Kawerau) mills in the North island of New Zealand have been used to assess the characteristics of colour removal by Lake Rotorua diatoms. Vacuum filtration through the diatoms succeeded in removing colour but proved to be impractically slow as an industrial process. Addition of diatoms to wastewater streams in stirred experiments showed that significant adsorption took place. The majority of the colour was removed within 30 seconds of mixing. The efficiency of colour removal was found to vary between wastewater streams within the mills. The pH dependency of this removal was tested and found to be most effective in a pH range of 3.6 to 5. Attempts to reuse the diatoms showed that chemical backwash regimes were more effective than calcination. This study concluded that surface silanols were likely to be the principle agent in forming coagulants with the colour material and were subsequently trapped on the diatom surfaces, but more importantly within the pores.

The aim of this thesis is to develop an technical aid (software) to help people with colourblindness. Colour blind people have difficulties to differentiate between certain colours,so the implemented software will name a selected colour. The software is implementedas a Mozilla Firefox extension and also uses a XPCOM component. Furthermore canthe user select different colour databases and change the displaying properties.The aim of this thesis is to develop an technical aid (software) to help people with colourblindness. Colour blind people have difficulties to differentiate between certain colours,so the implemented software will name a selected colour. The software is implementedas a Mozilla Firefox extension and also uses a XPCOM component. Furthermore canthe user select different colour databases and change the displaying properties.

Techniques of colour measurement and colour reproduction are important in a wide range of commercial and social activities in most modern economies. Their study thus constitutes one of the major areas of interest to the CIE. The project described in this thesis began as an outgrowth of studies of new types of light sources and of the colorimetry of colour-TV systems; plus a conviction that modern TV cameras can operate effectively with a wide range of different illuminating spectra. It was soon evident that two important prerequisites for this research were: an understanding of the processes of human colour vision; and a knowledge of the standard, international, colorimetric terminology of the CIE. These topics are discussed fully in the text. Also included is a review of modern gas-discharge lamps, the~y properties, and their applications. Both high-pressure (HID) types and low-pressure (fluorescent-tube) types are considered. Because of the need to measure the colours of surfaces and their TV reproductions as accurately as possible, various forms of colorimeter were examined, leading to the choice of a spectrophotometer system for this work. The design, construction, and evaluation of an original spetrophotometer system (the UND Spectrophotometer) are described fully in the text. Finally, attention is given to the operation of a television system under nonstandard lighting. Twelve different light sources were evaluated as TV ((taking" illuminants, using both subjective and colorimetric methods of assessment. The experimental results tend to confirm that colorimetric methods are unsuited to colour reproduction evaluation, and that subjective methods are more meaningful. A subjective scale of colour reproduction performance was established, and it was found to correlate closely with the CIE general colour rendering index (Ra) for the various test lamps. The work reported herein predates similar experiments with TV lighting by other workers, and it includes a wider range of light sources. In spite of differences in experimental technique, however, there is broad agreement with their general results. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 1987.

This thesis looks at the poetics of colour in Stefan George, Rainer Maria Rilke, Wassily Kandinsky and Else Lasker-Schüler. It argues that focusing on colour words allows us to think more carefully about the sort of making that poetry, around the turn of the twentieth century, was seen to be, its purpose and effects. In doing so it thinks also about this making-about the ways that words can be seen as the material of poetry, the ways poems relate to objects, and are objects, the ways poets negotiate semantic space and communicability. While other accounts argue for the specificity of a particular period, author, or hue, I argue for the specificity of the medium, a conclusion which seems necessary when considering how these particular poets thought about and through colour. While the poets' projects differ, colour can be used in each case like a prism, to separate out their attitudes and commitments towards their medium and its place in the world. The combination of these four poets, which is, to the best of my knowledge, unique, also allows new connections to be seen, whether, facing inward, in terms of colour itself, or outward towards the commitments regarding the poem that an approach via colour exposes. The four poets share an interest in the involvement, and in some cases, aesthetic education, of readers, and in how and what we can learn through reading, and particularly reading colour. What we learn has less to do with colours and how they are experienced than to do with the constructed world of the poem and its mechanisms, and of the role we have to play in animating this world.

Colour is an important source of information in the natural world. It can be used for distinguishing and identifying surfaces and objects and separating one region from another. For instance, flowers and grasses in a garden can be distinguished by their colours despite a change in illuminant. Intuitively, the identifiability of surfaces in a scene can be described by their volumes of colour gamuts. But is this approximation of the identifiability accurate? On the other hand, the existence of metamerism in natural scenes shows that colour is sometimes unreliable for surfaces identification. Estimating frequency of metamerism normally requires many comparisons between surface colours to determine their distinguishability under different illuminants. Is there a simpler approach to predict the frequency of metamerism in natural scenes? The aim of this thesis was to address these two questions about the identifiability of surfaces in natural scenes. To answer the first question, the volumes of colour gamuts were estimated over 50 natural scenes under different illuminants. The logarithm of the gamut volume was regressed on the differential entropy of colours. It was found that gamut volume can be an accurate approximation, given a colour difference threshold representing the visual distinguishability within an approximately perceptually uniform colour space. To answer the second question, the frequency of metamerism was estimated over 50 natural scenes with changes in illuminant; and predictive models were constructed based on different combinations of Shannon differential entropies of colours. There was strong dependence of the frequency of metamerism on the combination of the differential entropy and the conditional differential entropy of colours. It means that the frequency of metamerism can be predicted by the informational quantities of the colours in a scene.

No / This paper describes a novel approach to the fusion of multidimensional images for colour displays. The goal of the method is to generate an output image whose gradient matches that of the input as closely as possible. It achieves this using a constrained contrast mapping paradigm in the gradient domain, where the structure tensor of a high-dimensional gradient representation is mapped exactly to that of a low-dimensional gradient field which is subsequently reintegrated to generate an output. Constraints on the output colours are provided by an initial RGB rendering to produce ‘naturalistic’ colours: we provide a theorem for projecting higher-D contrast onto the initial colour gradients such that they remain close to the original gradients whilst maintaining exact high-D contrast. The solution to this constrained optimisation is closed-form, allowing for a very simple and hence fast and efficient algorithm. Our approach is generic in that it can map any N-D image data to any M-D output, and can be used in a variety of applications using the same basic algorithm. In this paper we focus on the problem of mapping N-D inputs to 3-D colour outputs. We present results in three applications: hyperspectral remote sensing, fusion of colour and near-infrared images, and colour visualisation of MRI Diffusion-Tensor imaging.

No / We present a numerical analysis of rendered pairs of rooms, in which the spectral power distribution of the illuminant in one room matched the surface reflectance function in the other room, and vice versa. We ask whether distinction between the rooms is possible and on what cues this discrimination is based. Using accurately rendered three-dimensional (3D) scenes, we found that room pairs can be distinguished based on indirect illumination, as suggested by A. L. Gilchrist and A. Jacobsen (1984). In a simulated color constancy scenario, we show that indirect illumination plays a pivotal role as areas of indirect illumination undergo a smaller appearance change than areas of direct illumination. Our study confirms that indirect illumination can play a critical role in surface color recovery and shows how computer rendering programs, which model the light¿object interaction according to the laws of physics, are valuable tools that can be used to analyze and explore what image information is available to the visual system from 3D scenes.

No / We have previously shown (Bloj et al., 2008; Abstracts Materials & Sensations 2008) that under particular conditions colour memory is independent of presentation media, and of the illuminants under which colours are viewed. In the present study we investigate whether colour naming is also unaffected by these two factors. Forty-eight colour samples from the Natural Colour System (NCS) collection were presented as real paper samples or as accurate computer simulations displayed on a calibrated monitor. The colour swatches could be presented under a daylight illuminant ¿ two intensities, 85 ( D1 ) or 60 cd m)2 ( D2 ) ¿ or a purple illuminant, 45 cd m)2 ( Lily ). The colour samples were shown in arrays of 16 (4 · 4 layout) and the observer s task was to assign one of the eleven basic colour terms to each of the samples. Six observers repeated this colour naming task five times for each presentation medium and illuminant. On average, in 73% of the cases the same colour term was assigned to surface and display colours. This level of agreement was highest for colour samples under daylight (D1-82%, D2-73%) and poor for Lily (65%). Although colour memory is unaffected by the nature of the colour stimulus, here we show that there are limitations to cross-media agreement in colour naming.