16 research outputs found
The Holographic Stereogram
The holographic stereogram, a hologram synthesized from ordinary
stereoscopic component photographs, is investigated as an alternative to classical
holograms and to previous types of stereograms for three-dimensional perfect
imagery. The process is partly holographic in nature, but it provides images of
naturally illuminated objects, and its application is not limited by the technology
of laser illumination. The pinhole camera stereogram and the fly's eye lens
stereogram are also analyzed, since the principles of their operation are similar.
Pinhole camera stereogram imagery is shown to have several deficiencies, among
which is the necessity for small camera-object distances. The fly's eye lens is
much superior, but is limited in practice by aberrations, a difficulty which the
holographic stereogram overcomes. Also treated are the full-color, the focused type,
and the distortionless-scaled holographic stereogram, and optical spatial
filtering of holographic stereogram images.
The achromatically imaged Fresnel zone plate is analyzed as a technique
of very general applicability which compensates for source incoherency in two-beam
type holographic arrangements. The emphasis is on physical interpretation
rather than mathematical formulation. Two simple graphical mnemonics are
developed for rapid analytical inspection of the effects of, respectively, temporal
and spatial incoherence of the source in any achromatically imaged zone plate
or Gabor in-line type holographic system.
The scalar wave function approximation of physical optics is used
throughout.</p
Modern lithographic techniques applied to stereographic imaging
The main aim of the research has been to produce and evaluate a high-quality diffusion
screen to display projected film and television images. The screens have also been found
to effectively de-pixelate LCD arrays viewed at a magnification of approximately 4x.
The production process relies on the formation of localized refractive index gradients in a
photopolymer. The photopolymer, specially formulated and supplied by Du Pont, is
exposed to actinic light through a precision contact mask to initiate polymerization within
the exposed areas. As polymerization proceeds, a monomer concentration gradient exists
between the exposed and unexposed regions allowing the monomer molecules to diffuse.
Since the longer polymer chains do not diffuse as readily, the molecular concentration of
the material, which is related to its refractive index, is then no longer uniform. The
generation of this refractive index profile can, to some extent, be controlled by careful
exposure of the photopolymer through the correct mask so that the resulting diffusion
screen can be tailored to suit specific viewing requirements. [Continues.
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Holoscopic 3D imaging and display technology: Camera/ processing/ display
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonHoloscopic 3D imaging “Integral imaging” was first proposed by Lippmann in 1908. It has become an attractive technique for creating full colour 3D scene that exists in space. It promotes a single camera aperture for recording spatial information of a real scene and it uses a regularly spaced microlens arrays to simulate the principle of Fly’s eye technique, which creates physical duplicates of light field “true 3D-imaging technique”.
While stereoscopic and multiview 3D imaging systems which simulate human eye technique are widely available in the commercial market, holoscopic 3D imaging technology is still in the research phase. The aim of this research is to investigate spatial resolution of holoscopic 3D imaging and display technology, which includes holoscopic 3D camera, processing and display.
Smart microlens array architecture is proposed that doubles spatial resolution of holoscopic 3D camera horizontally by trading horizontal and vertical resolutions. In particular, it overcomes unbalanced pixel aspect ratio of unidirectional holoscopic 3D images. In addition, omnidirectional holoscopic 3D computer graphics rendering techniques are proposed that simplify the rendering complexity and facilitate holoscopic 3D content generation.
Holoscopic 3D image stitching algorithm is proposed that widens overall viewing angle of holoscopic 3D camera aperture and pre-processing of holoscopic 3D image filters are proposed for spatial data alignment and 3D image data processing. In addition, Dynamic hyperlinker tool is developed that offers interactive holoscopic 3D video content search-ability and browse-ability.
Novel pixel mapping techniques are proposed that improves spatial resolution and visual definition in space. For instance, 4D-DSPM enhances 3D pixels per inch from 44 3D-PPIs to 176 3D-PPIs horizontally and achieves spatial resolution of 1365 × 384 3D-Pixels whereas the traditional spatial resolution is 341 × 1536 3D-Pixels. In addition distributed pixel mapping is proposed that improves quality of holoscopic 3D scene in space by creating RGB-colour channel elemental images
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Holoscopic 3D image depth estimation and segmentation techniques
This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonToday’s 3D imaging techniques offer significant benefits over conventional 2D imaging techniques. The presence of natural depth information in the scene affords the observer an overall improved sense of reality and naturalness. A variety of systems attempting to reach this goal have been designed by many independent research groups, such as stereoscopic and auto-stereoscopic systems. Though the images displayed by such systems tend to cause eye strain, fatigue and headaches after prolonged viewing as users are required to focus on the screen plane/accommodation to converge their eyes to a point in space in a different plane/convergence. Holoscopy is a 3D technology that targets overcoming the above limitations of current 3D technology and was recently developed at Brunel University. This work is part W4.1 of the 3D VIVANT project that is funded by the EU under the ICT program and coordinated by Dr. Aman Aggoun at Brunel University, West London, UK. The objective of the work described in this thesis is to develop estimation and segmentation techniques that are capable of estimating precise 3D depth, and are applicable for holoscopic 3D imaging system. Particular emphasis is given to the task of automatic techniques i.e. favours algorithms with broad generalisation abilities, as no constraints are placed on the setting. Algorithms that provide invariance to most appearance based variation of objects in the scene (e.g. viewpoint changes, deformable objects, presence of noise and changes in lighting). Moreover, have the ability to estimate depth information from both types of holoscopic 3D images i.e. Unidirectional and Omni-directional which gives horizontal parallax and full parallax (vertical and horizontal), respectively. The main aim of this research is to develop 3D depth estimation and 3D image segmentation techniques with great precision. In particular, emphasis on automation of thresholding techniques and cues identifications for development of robust algorithms. A method for depth-through-disparity feature analysis has been built based on the existing correlation between the pixels at a one micro-lens pitch which has been exploited to extract the viewpoint images (VPIs). The corresponding displacement among the VPIs has been exploited to estimate the depth information map via setting and extracting reliable sets of local features. ii Feature-based-point and feature-based-edge are two novel automatic thresholding techniques for detecting and extracting features that have been used in this approach. These techniques offer a solution to the problem of setting and extracting reliable features automatically to improve the performance of the depth estimation related to the generalizations, speed and quality. Due to the resolution limitation of the extracted VPIs, obtaining an accurate 3D depth map is challenging. Therefore, sub-pixel shift and integration is a novel interpolation technique that has been used in this approach to generate super-resolution VPIs. By shift and integration of a set of up-sampled low resolution VPIs, the new information contained in each viewpoint is exploited to obtain a super resolution VPI. This produces a high resolution perspective VPI with wide Field Of View (FOV). This means that the holoscopic 3D image system can be converted into a multi-view 3D image pixel format. Both depth accuracy and a fast execution time have been achieved that improved the 3D depth map. For a 3D object to be recognized the related foreground regions and depth information map needs to be identified. Two novel unsupervised segmentation methods that generate interactive depth maps from single viewpoint segmentation were developed. Both techniques offer new improvements over the existing methods due to their simple use and being fully automatic; therefore, producing the 3D depth interactive map without human interaction. The final contribution is a performance evaluation, to provide an equitable measurement for the extent of the success of the proposed techniques for foreground object segmentation, 3D depth interactive map creation and the generation of 2D super-resolution viewpoint techniques. The no-reference image quality assessment metrics and their correlation with the human perception of quality are used with the help of human participants in a subjective manner
Scientific and technological progress. Advantages and disadvantages
The theme under consideration is divided into two parts: The History of Telephone and Innovations in Telephone Communications.
In the past, people relied on letters to learn about what was going on in the lives of their friends or family members.
The first electrical telegraph was constructed by Sir William Cooke. Another telegraph was developed and patented in the USA in 1837 by Samuel Morse.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2807
Marking time: investigating drawing as a performative process for recording temporal presence and recalling memory through the line, the fold and repetition
This research seeks to identify drawing as an alternative exemplar for investigating memory and temporal presence, while determining its potential as a performative tool for negotiation and transformation, throught the line, fold and repetition. The aim is to position drawing in the dynamics of movement, using the journey as a trope and the physical act of repeating the line to evoke memory and disrupt concepts of linear, orderly time.
The investigation, driven by my ongoing practice and concerns of dislocation and exile, was inspired and informed by Gilles Deleuze's notion of 'becoming' as a fluid in-between. His reading of memory through Henri Bergson (habit and pure) and Marcel Proust(voluntary and involuntary), provided the context for examining drawing's memorial potency along a past-present-future continuum. Deleuze's ontology provided a reflective and reflecive methodology for addressing my own work alongside artists who share similar concerns.
My practice focused on not what the line is but what it can do or be, where drawing is predicated on touch and derived from thought and memory, rather than appearance or observation. Inside the studio and outdoors in the landscape, moving between familiar yet changed places. I marked the paradoxical experience of time, its flows and ruptures. The resulting body of drawings and photographic records offer the principal outcome of this inquiry.
The research findings present drawing as a fluid multiplicity that shifts between the haptic and optic, visible and invisible, control and chance, notation and photography, studio and street, with one often constituting the other. The condition of 'seeing' is not a prerequisite; drawing exists with and without seeing. It resides in a gap between, where time itself unfolds and things are forgotten as well as remembered, liminal and open-ended. This thesis proposes a new theoretical understanding of drawing as generative of memory and a process of continual negotiation and temporal becoming
The Postnatural Animal in Contemporary Art
The thesis uses art practice as a research method to propose novel characterisations of animal life. These characterisations aim to challenge an organicist image of non-human animals. The thesis considers animal bodies and behaviours as subject to aesthetic judgments that are underpinned by deeper ontological and epistemological commitments as to relations between nature and society, in which to be categorised as the former entails a series of privations in relation to the latter – the absence of freedom, subjectivity and creativity. Scholarly research on the history of the perception and conception of animal life within modernity, and subsequent challenges made to these within the contemporary humanities and contemporary art support and inform the practical enquiry. The thesis draws primarily here upon new materialist and post-humanist-oriented animal studies, and on scholarship surrounding the contemporary French artist, Pierre Huyghe.
Positing the Anthropocene as a condition in which the distinction between human history and natural history has collapsed, the thesis argues for disassociating the concept ‘animal’ and the concept ‘nature’. The thesis attends to entanglements of animal worlds and cultural tropes where this equation fails. It proposes an an-organic and dis-harmonious animal life that attest to the end of nature and witnesses the dissonant and incomplete conditions of modernity. Both the written argument and the artistic outcomes propose novel ways to consider animals in relation to visuality. The thesis takes bio-art (i.e., art practice that incorporates living organisms) as of methodological value in this project where it engages the potentiality of animals themselves to challenge a received historical status. Furthermore, art practice is not just seen as a vehicle for depicting animal futures, but as a condition for liberating animals from nature. The thesis thus equates the postnatural animal with their becoming agents within artworks