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Human Vision (human + vision)
Selected AbstractsRepresentation of Pseudo Inter-reflection and Transparency by Considering Characteristics of Human VisionCOMPUTER GRAPHICS FORUM, Issue 3 2002H. Matsuoka We have succeeded in developing a quick and fully automated system that can generate photo-realistic 3D CG data based on a real object. A major factor in this success comes from our findings through psychophysical experiments that human observers do not have an accurate idea of what should be actually reflected as inter-reflections on the surface of an object. Taking advantage of this characteristic of human vision, we propose a new inter-reflection representation technique in which inter-reflections are simulated by allowing the same quantity of reflection components as there are in the background to pass through the object. Since inter-reflection and transparency are calculated by the same algorithm, our system can capture 3D CG data from various real objects having a strong inter-reflection, such as plastic and porcelain items or translucent glass and acrylic resin objects. The synthetic images from the 3D CG data generated with this pseudo inter-reflection and transparency look very natural. In addition, the 3D CG data and synthetic images are produced quickly at a lower cost. [source] The lenses of nationhood: an optical model of identityNATIONS AND NATIONALISM, Issue 3 2008ERIC KAUFMANN ABSTRACT. This paper tries to make the case for a model of political identity based on an optical metaphor, which is especially applicable to nations. Human vision can be separated into sentient object, lenses and inbuilt mental ideas. This corresponds well to identity processes in which ,light' from a bounded territorial referent is refracted through various lenses (ideological, material, psychological) to focus in certain ways on particular symbolic resources like genealogy, history, culture or political institutions. Distinguishing between referent, lenses and resources helps us more precisely situate many hitherto disparate problems of national identity. These include the ,ethnic-civic' dilemma, the mystery of national identity before nationalism, and the relationship between local and national, and individual and collective, identities. The model also clarifies the place of universalist ideology, which currently fits poorly within the leading culturalist and materialist theories of nationalism. [source] Representation of Pseudo Inter-reflection and Transparency by Considering Characteristics of Human VisionCOMPUTER GRAPHICS FORUM, Issue 3 2002H. Matsuoka We have succeeded in developing a quick and fully automated system that can generate photo-realistic 3D CG data based on a real object. A major factor in this success comes from our findings through psychophysical experiments that human observers do not have an accurate idea of what should be actually reflected as inter-reflections on the surface of an object. Taking advantage of this characteristic of human vision, we propose a new inter-reflection representation technique in which inter-reflections are simulated by allowing the same quantity of reflection components as there are in the background to pass through the object. Since inter-reflection and transparency are calculated by the same algorithm, our system can capture 3D CG data from various real objects having a strong inter-reflection, such as plastic and porcelain items or translucent glass and acrylic resin objects. The synthetic images from the 3D CG data generated with this pseudo inter-reflection and transparency look very natural. In addition, the 3D CG data and synthetic images are produced quickly at a lower cost. [source] The Influence of Dietary Lutein and Zeaxanthin on Visual PerformanceJOURNAL OF FOOD SCIENCE, Issue 1 2010James M. Stringham ABSTRACT:, The idea that normal constituents of the diet can influence visual function is not new. As early as 1782, Buzzi identified the yellow of the macula and Schulze (1866) specifically postulated that the yellow pigments led to improvements in human vision. These pigments were later found to be derived from dietary lutein and zeaxanthin that are known to be oxygenated carotenoids (xanthophylls). Walls and Judd (1933) postulated that these yellow intraocular pigments could improve visual performance by absorbing light scattered both within (for example, glare) and outside of the eye (increasing visual range by absorbing blue light scattered in the atmosphere), and by improving spatial vision through enhancing contrast and reducing chromatic blur. In this article, evidence for these ideas is reviewed with particular emphasis towards more recent data on glare effects. [source] The Reformation of the Eyes: Apparitions and Optics in Sixteenth- and Seventeenth-Century EuropeJOURNAL OF RELIGIOUS HISTORY, Issue 2 2003Stuart Clark Apparitions were the subject of fierce theological and philosophical debate in the period after the Reformation. But these controversies also raised issues fundamental to the nature and organization of human vision. They crossed and recrossed the boundaries between religion and the science and psychology of optics. Apparitions, after all, are things that appear, and spectres are things that are seen. Before they could mean anything to anyone they had to be correctly identified as phenomena. Their religious role, whether Protestant or Catholic, presupposed a perceptual judgement , essentially visual in character , about just what they were. During the early modern period this judgement , this visual identification , became vastly more complex and contentious than ever before, certainly much more so than in the case of medieval ghosts. The sceptics, natural magicians, and atheists turned apparitions into optical tricks played by nature or human artifice; the religious controversialists and demonologists thought that demons might also be responsible. This essay argues that the debate that ensued, irrespective of the confessional allegiances of the protagonists, was the occasion for some of the most sustained and sophisticated of the early modern arguments about truth and illusion in the visual world. [source] Temporal detection in human vision: dependence on eccentricityOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 2 2002R. F. Hess Studies of human perception of time-varying luminance often aim to estimate either temporal impulse response shapes or temporal modulation transfer functions (MTFs) of putative temporal processing mechanisms. Previously, temporal masking data have been used to estimate the properties and numbers of these temporal mechanisms in central vision for 1 cycle per degree (cpd) targets [Fredericksen and Hess (1998)]. The same methods have been used to explore how these properties change with stimulus energy [Fredericksen and Hess (1997)] and spatial frequency [Fredericksen and Hess (1999)]. We present here analyses of the properties of temporal mechanisms that detect temporal variations of luminance in peripheral vision. The results indicate that a two-filter model provides the best model for our masking data, but that no multiple filter model provides an acceptable fit across the range of parameters varied in this study. Single-filter modelling shows differences between processing mechanisms at 1 cpd in central vision and those that operate eccentrically. We find evidence that this change is because of differences in relative sensitivities of the mechanisms, and to differences in fundamental mechanism impulse responses. [source] Perceptual considerations in the use of colored photographic and video stimuli to study nonhuman primate behaviorAMERICAN JOURNAL OF PRIMATOLOGY, Issue 11 2006Corri Waitt Abstract The use of photographs, slides, computerized images, and video to study behavior is increasingly being employed in nonhuman primates. However, since these mediums have been designed to simulate natural coloration for normal trichromatic human vision, they can fail to reproduce color in meaningful and accurate ways for viewers with different visual systems. Given the range of color perception that exists both across and within different species, it is necessary to consider this variation in order to discern the suitability of these mediums for experimental use. Because of the high degree of visual similarity among humans, Old World monkeys, and apes, the use of photographic and video stimuli should be acceptable in terms of replicating naturalistic coloration and making noticeable color manipulations. However, among New World primates and prosimians, there exists a considerable degree of variation in color perceptual abilities depending on the species, sex, and allelic combination of the animals involved. Therefore, the use of these mediums to study behavior is problematic for these species, and should be done with caution. Am. J. Primatol. 68:1054,1067, 2006. © 2006 Wiley-Liss, Inc. [source] Colour and colour vision of creatures great and smallCOLORATION TECHNOLOGY, Issue 2 2006Tim L Dawson Today the mechanisms of human colour vision are well understood because of the detailed communication feedback possible in experimental studies. The situation with other species in the animal kingdom is less easy to investigate and understand. In the present review, examples of the colour and colour vision of various animal species are described, selected mainly because they are particularly interesting and indeed colourful. The chemical structures and the relationships of the natural pigments involved also receive attention. Despite many decades of vision research, many aspects of colour vision remain unclear. Nevertheless increasing knowledge in all these fields may someday help to elucidate the neurological pathways underlying other animals' colour vision to the same extent as is at present known for human vision. [source] | |||||||||||||