Show filters Hide filters

Refine your search

Publication Year
1-36 out of 47 results
Change view
  • Sort by:
21:46 River Valley TV English 2012

Artistic Representation with Pulsed Holography

This thesis describes artistic representation through pulsed holography. One of the prevalent practical problems in making holograms is object movement. Any movement of the object or film, including movement caused by acoustic vibration, has the same fatal results. One way of reducing the chance of movement is by ensuring that the exposure is very quick; using a pulsed laser can fulfill this objective. The attractiveness of using pulsed laser is based on the variety of materials or objects that can be recorded (e.g., liquid material or instantaneous scene of a moving object). One of the most interesting points about pulsed holograms is that some reconstructed images present us with completely different views of the real world. For example, the holographic image of liquid material does not appear fluid; it looks like a piece of hard glass that would produce a sharp sound upon tapping. In everyday life, we are unfamiliar with such an instantaneous scene. On the other hand, soft-textured materials such as a feather or wool differ from liquids when observed through holography. Using a pulsed hologram, we can sense the soft touch of the object or material with the help of realistic three-dimensional (3-D) images. The images allow us to realize the sense of touch in a way that resembles touching real objects. I had the opportunity to use a pulsed ruby laser soon after I started to work in the field of holography in 1979. Since then, I have made pulsed holograms of activities, including pouring water, breaking eggs, blowing soap bubbles, and scattering feathers and popcorn. I have also created holographic art with materials and objects, such as silk fiber, fabric, balloons, glass, flowers, and even the human body. Whenever I create art, I like to present the spectator with a new experience in perception. Therefore, I would like to introduce my experimental artwork through those pulsed holograms.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
24:08 River Valley TV English 2012

A transportable system for the in situ recording of color Denisyuk holograms in silver-halide panchromatic emulsions and an optimized illumination device.

In this paper we will present the Z-Lab transportable color holography system, the HoloPhos illuminator and results of actual in situ recording of color Denisyuk holograms of artifacts on panchromatic silver halide emulsions. Z-lab and HoloPhos were developed to meet identified prerequisites of holographic recording of artifacts: a) in situ recording b) a high degree of detail and color reproduction c) a low degree of image distortions. The Z-Lab consists of the Z-3 camera, its accessories and a mobile darkroom. The Z-3 camera is a computer controlled opto mechanical device capable of exposing selected, commercially available, panchromatic silver halide emulsions to the combined red, green and blue laser beams at sufficient energy levels. Z-3 accessories include a vibration isolation platform and custom plate holders in the object’s space. The mobile darkroom is autonomous and environmentally friendly with closed circuits for chemical waste management. HoloPhos is an RGB LED based lighting device for the display of color holograms. The device is capable of digitally controlled intensity mixing and provides a beam of uniform color cross section. The small footprint and emission characteristics of the device LEDs result in a quasi point, narrow bandwidth, source at selected wavelengths. A case study in recording and displaying Greek cultural heritage artifacts with the aforementioned systems will also be presented.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:24 River Valley TV English 2012

Bit-mapped holograms using phase transition mastering (PTM) and Blu-ray disks

Due to recent advances made in data storage, cloud computing, and Blu-ray mastering technology, it is now straight forward to calculate, store, transfer, and print bit-mapped holograms that use terabytes of data and tera-pixels of information. This presentation reports on the potential of using the phase transition mastering (PTM) process to construct bit-mapped, computer generated holograms with continuous-tone phase levels and spatial resolutions of 5000 line-pairs/mm (70 nm pixel width). In particular, for Blu-ray disk production, Sony has developed a complete process that could be alternately deployed in holographic applications. The phase transition mastering (PTM) process uses a 405 nm laser to write phase patterns onto a layer of imperfect transition metal oxides that is deposited onto an 8 inch silicon wafer. After the master hologram has been constructed, its imprint can then be cheaply mass produced with the same process as Blu-ray disks or embossed holograms. Unlike traditional binary holograms made with expensive e-beam lithography, the PTM process enables continuous phase levels using inexpensive optics similar to consumer-grade desk-top Blu-ray writers. This PTM process could revolutionize holography for entertainment, industrial, and scientific applications. The author has filed a Provisional Patent on the application of PTM in holography.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
18:18 River Valley TV English 2012

An innovative tool for fabrication of computer generated holograms

Based on research at MIT, LumArray, Inc. has developed a maskless photolithography tool, the ZP-150, designed to cover an entire 6-inch substrate with a continuous, coherent high-resolution pattern, thereby avoiding the “stitching problem” and making it ideal for fabricating computer-generated holograms (CGH). No mask is required, as data is transferred directly from a computer to a spatial-light modulator that adjusts the intensity of 1000 beamlets, and directs them to 1000 diffractive-optical lenses. Patterns of arbitrary geometry, with placement precision ~1nm, are written by scanning the stage in coordination with modulation of the beamlets by the spatial-light modulator. The throughput of one 6-inch wafers per hour far exceeds that of electron-beam lithography. A fully automated proximity-effect-correction algorithm enables fine and large features to be written with equal ease, as well as the creation of 3-D structures. The ZP-150 uses stable, non-chemically amplified photoresists. Extension of resolution from the current 150 nm to the sub-100 nm domain is planned. In addition to providing rapid turn around on designs, we envisage the ZP-150 being used in customized manufacturing of CGH’s by virtue of its modest cost and low maintenance.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
25:27 River Valley TV English 2012

A curious conundrum; the state of holographic portraiture in the 21st century

The technology of producing (true) hologram portraits was first introduced in the late 1960’s. From this time, a number of individuals and organizations worldwide have specialized in providing holographic portraiture services with varying degrees of achievement. Yet today, some 45 years later, holographic portraiture remains an obscure and niche form of displaying an individual’s likeness. Despite all of this technology’s promising and unique attributes, and the astonishing fact of holography being the most accurate and realistic form of imaging available today; true holographic portraiture continues to be a form of portraiture largely unknown to the general public and has never achieved large-scale commercial success. This paper will present a brief history of holographic portraiture, designating the different types of 3-D hologram portraits available today, and their uses. Emphasis will be given to true holographic pulsed portraiture in which the subject itself is recorded holographically using high-energy pulsed lasers. Possible cause and effect for explaining the present demise of this type of portrait making will be discussed along with recent advancements and future developments in this fledgling field which could ultimately lead to a “tipping point” in large-scale consumer and commercial awareness and desirability of the medium. The author will share his experiences in operating pulsed holographic portraiture studios for over the last 15 years including the vision of a new type of holographic portrait studio for the 21st century which he hopes will attain the level of success enabling a next generation of commercially viable holographic portrait studios for the future.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
18:14 River Valley TV English 2012

An easy physics outreach and teaching tool for holography

In the framework of scientific outreach and teaching purposes at the Aix-Marseille University, we created a pedagogic “holographic case”. With a small size (34 cm x 25 cm x 16 cm) for 2.5 kg, the case includes all the required equipment to produce very good quality holograms with a simple optical assembly and an excellent vibration tolerance. The case allows illustrating fundamental principle of holography and its applications : holographic interferometry, angular multiplexing (HVD) and “Notch” filters. The success rate with this device approaches 100%, and has been tested in very noisy environments. Moreover, this device can reach a very large audience and a very low cost version is studied. We use it at the “science house” of Aix Marseille University for outreach purpose for primary school to high school workshops. The holographic case is also used for teaching purpose at university for undergraduate and graduate students. Finally, we use it to train teachers to holography, who use holography for their own pedagogic projects. In this article, we explain how the case works, and give some applications and results that can be done with it.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
17:37 River Valley TV English 2012

A holographic collaboration

In the Fall oF 87 Rudie Berkhout and myself started a very intense and fruitful collaboration producing a series of holographic art pieces that were experimental but that reflected our different artistic sensibilities. The masters were made in my portrait studio in the Museum of Holography in New York using a pulse laser and later transferred in my Long Island City studio. These pieces were shown at the Holocenter in 2009 and poignantly, it was the last show that Rudie had while he was alive. My paper details the process of an artistic collaboration, its pitfalls and advantages, its conflicts and compromises. It will illuminater the creative process that from two separate and very different streams melded into beautiful and evocative art
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:38 River Valley TV English 2012

Across Light: Through Colour II

This paper intends to be a reflection on the end product of the process of preparing movies to digital art holograms, comparing the kind of space and movement between those images and the ones in the previous paper. This paper explores too questions about the act of seeing through that images and it is concerned with the surrounding debate of ideas for new experimental methodologies applied to holographic images.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:43 River Valley TV English 2012

Aberrations in holography

The Seidel aberrations are described as they apply to holography. Methods of recognition of an aberrated holographic reconstruction are described, as well as a recognition of the type of aberration. Experimental and theoretical strategies to minmise aberations are discussed, including geometric considerations in the recording and reconstruction of holograms. Aberrations due to the recording of a hologram with one wavelength and reconstructing it in another is also examined.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
19:41 River Valley TV English 2012

For a photon there is only the present

Several years ago I produced a hologram using the pulsed laser at the Center for Holographic Art, New York to explore an idea illustrated by the ancient Hindu story of Indra’s Net. The optically active model created a secondary set of images surrounding the reconstruction source. Upon close examination, the elements of the objects formed a complex Gabor hologram centered in an array of multi-referenced images. The multiple layers of images suggest the infinite reflections of the Indra’s Net story and parallel both ancient and contemporary concepts of complexity. This paper will present new works using holography to explore the paradoxical nature of light.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:22 River Valley TV English 2012

From mimetism to immateriality in art holography: different approaches and concepts

Being Holography, so far, the recording technology that represents the object most similar to the original, with the same parallax, it allows a mimetic representation of reality. But is that the only purpose for an artistic work in this medium? Holography is a pure light medium. It also offers the unique quality of presenting rather than representing light qualities such as immateriality, invisibility, and the recording of several images in the same space, which invites artists to explore and express in those types of subjects. How do artists use Holography as a resource for developing their own artistic language? Approaching it in different ways makes holography to be a especial suitable medium for Conceptual Art works. And there is no greater dematerialized energy than the light itself, which is the essence of the holographic image. Therefore, materiality is reduced to the support in the case of the holography medium. This paper aims to reflect and enhance the characteristics of Holography as an artistic medium in the moment that new approaches and techniques such as stereoscopic projection (several times wrongly called holography) 3D movies and video and augmented reality are being developed and divulged.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
23:35 River Valley TV English 2012

Drawing lightfields: handdrawn approaches to abrasion holography

The depth illusion apparent in light reflected from circular scratch patterns has been noted independently by many commentators since the 1930’s (e.g. Weil, 1934; Lott, 1963; Walker, 1989). In the early 1990’s William Beaty compared this illusion to holography and formalized a technique for creating 3D drawings by hand, which he called “scratchograms” or “abrasion holography.” Several recent publications (Regg et al., 2010; Augier & Sánchez, 2011; Brand, 2011) explore computer-aided methods of producing abrasion-type holograms, using CNC engravers, and milling machines. Very little, however has been published in the way of expanding the techniques available for hand drawing abrasion holograms. I explore new, hand-drawn approaches to abrasion holography, presenting a variety of techniques that expand the possibilities of the medium. Complex curves and organic forms can be constructed by hand more easily and intuitively than previously described methods, allowing for more diverse and artistic effects to be achieved. In an analysis of reconstruction lighting and viewing geometries, I suggest solutions to reduce or eliminate distortions present in abrasion holograms (such as the “swinging” sensation experienced with motion parallax). Various tools, materials, and scratch geometries are considered. I also present a new class of hand-drawn abrasion holograms that exhibit novel animation effects. In conclusion, I outline preliminary findings related to the duplication of hand-drawn holograms using a simple foil embossing process. I detail these findings along with illustrations and test plates. I also will show examples of artistic works exploring the medium of hand-drawn abrasion holography. In the field of hand-drawn abrasion holography we have, so to speak, only scratched the surface of what is possible. As a medium, hand-drawn abrasion holography offers many interesting and as-yet unexplored possibilities. It is my hope that the investigation presented here will inspire further exploration of this unique medium.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
19:18 River Valley TV English 2012

Design and visualization of synthetic holograms for security applications

Today, the synthetic holograms are widely used in optical document security, where various visual effects are utilized for evaluation of originality of the security element. The security function is based on a very fine micro-structure with details of order of hundreds of nanometres. It diffracts the light and creates macroscopic visual effects. Very important property of this kind of elements is ability of common observer to check the originality of the element without any sophisticated knowledge of the optical principles and usually also without any additional tools. Thus the visual design of the element plays an important role not only from an artistic point of view, but also from a point of view of security function of the element. When the designed element contains many different visual effects, it is difficult for the designer to imagine the complex behavior of the hologram. Moreover, it is almost impossible to present the hologram properties to most customers, who are not familiar with the holography at all. In this paper we present our developed software for design and visualization of holographic elements containing full scale of visual effects. It enables to simulate observation of holographic elements under general conditions including different light sources with various spectral and coherence properties and various geometries of reconstruction. Furthermore, recent technologies offer interesting possibilities for 3D visualization such as 3D techniques based on shutter or polarization glasses, etc. The presented software is compatible with the mentioned techniques and enables application of 3D hardware tools. The software package can be used not only for visualization of existing designs, but also for fine tuning of spatial, kinetic, and color properties of the hologram. Moreover, holograms containing all types of 3D effects, general color mixing, kinetic behavior, diffractive cryptograms, etc. can be translated directly to a high resolution micro-structure.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
15:35 River Valley TV English 2012

Full parallax three-dimensional computer generated hologram with occlusion effect using ray casting technique

Holographic display is capable of reconstructing the whole optical wave field of a three-dimensional (3D) scene. It is the only one among all the 3D display techniques that can produce all the depth cues. With the development of computing technology and spatial light modulators, computer generated holograms (CGHs) can now be used to produce dynamic 3D images of synthetic objects. Computation holography becomes highly complicated and demanding when it is employed to produce real 3D images. Here we present a novel algorithm for generating a full parallax 3D CGH with occlusion effect, which is an important property of 3D perception, but has often been neglected in fully computed hologram synthesis. The ray casting technique, which is widely used in computer graphics, is introduced to handle the occlusion issue of CGH computation. Horizontally and vertically distributed rays are projected from each hologram sample to the 3D objects to obtain the complex amplitude distribution. The occlusion issue is handled by performing ray casting calculations to all the hologram samples. The proposed algorithm has no restriction on or approximation to the 3D objects, and hence it can produce reconstructed images with correct shading effect and no visible artifacts. Programmable graphics processing unit (GPU) is used to perform parallel calculation. This is made possible because each hologram sample belongs to an independent operation. To demonstrate the performance of our proposed algorithm, an optical experiment is performed to reconstruct the 3D scene by using a phase-only spatial light modulator. We can easily perceive the accommodation cue by focusing our eyes on different depths of the scene and the motion parallax cue with occlusion effect by moving our eyes around. The experiment result confirms that the CGHs produced by our algorithm can successfully reconstruct 3D images with all the depth cues.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:12 River Valley TV English 2012

Discrete calculation of the off-axis angular spectrum based light propagation

Light propagation in a free space is a common computational task in many computer generated holography algorithms. A solution based on angular spectrum decomposition is used frequently. However, its correct off-axis numerical implementation is not straightforward. It is shown that for long distance propagation it is necessary to use digital low-pass filtering for transfer function calculation in order to restrict source area illumination to a finite area. It is also shown that for short distance propagation it is necessary to introduce frequency bands folding in transfer function calculation in order to simulate finite source area propagation. In both cases it is necessary to properly define interpolation filters that reconstruct continuous nature of the source area out of its sampled representation. It is also necessary to properly zero-pad source area sampling in order to avoid artifacts that stem from the periodic nature of the fast Fourier transform.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:35 River Valley TV English 2012

Going deeper: teaching more than the mechanics

What follows is a description of an introductory holography course titled “Lasers and Holography,” taught by the author at Columbia College Chicago since 1997. Because this is a science class at an arts college with an open admissions policy, these students have many different levels of education, dissimilar backgrounds, and varied fields of interest. There are no science majors. Therefore, specific learning objectives have been developed. The author contends that for many of these students it is not enough to teach the physics of making holograms. To inspire and instill a lifelong appreciation for science and physics, one must go still deeper. Students need to be touched on more than just an intellectual level. Consequently, a broader approach is used. Ultimately, students may be stirred to want to learn more, and to be confident they can. The paper addresses: 1. Becoming aware of one’s individual state of seeing 2. Perceptual illusions: their impact on the advancement of science and art 3. Promoting artistic applications and exposing students to fine art holography 4. Teaching holography as an information processing, as well as an image-making technology 5. Introducing and exploring philosophical implications of holographic principles.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
14:50 River Valley TV English 2012

Flying with Antares DLR-H2 -from stereo images to multiview

The digital hologram of the 4D arrival management system of flight guidance, the holographic animation of the Reichstag in Berlin, a flight with the atoms in a fuel cell for a glasses free multi barrier monitor and the first electric noiseless hydrogen driven plane of the world, the Antares H2 documented with a stereo rig: The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; in this text used DLR) researches give an incredible data base for new image making, which, some artists, like the author, have transformed into a visual stage. The outputs of 3D illustrations have been in S3D, M3D and holographic media.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:12 River Valley TV English 2012

Haptic holography/touching the ethereal

Haptic Holography, was perhaps, first proposed by workers at MIT in the 80s. The Media Lab, headed up by Dr. Stephen Benton,with published papers by Wendy Plesiak and Ravi Pappuh. Recent developments in both the technology of digital holography and haptics have made it practical to conduct further investigations. Haptic holography is auto-stereoscopic and provides co-axial viewing for the user. Haptic holography may find application in medical & surgical training and as a new form of synthetic reality for artists and designers.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
15:00 River Valley TV English 2012

Direct optical fringe writing of of diffraction specific coherent panoramagrams in photorefractive polymer for updatable three-dimensional holographic display

  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
10:29 River Valley TV English 2012

A holographic color camera for recording artifacts

Advent of 3D televisions has created a new wave of public interest in 3D images. Though these technologies create moving pictures with apparent depth, it lacks the visual appeal and a set of other positive aspects of color holographic images. But, the above new wave of interest in 3D will definitely help to fuel popularity of holograms. In view of this, a low cost and handy color holography camera is designed for recording color holograms of artifacts. It is believed that such cameras will help to record medium format color holograms outside conventional holography laboratories and help in popularization of color holography. The paper discusses the design and the results obtained.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
16:42 River Valley TV English 2012

A stellar hologram

Holorad has produced a very large (1.95×1.95m) transmission hologram for the American Museum of Natural History (AMNH) in New York City, illustrating the distribution of planets discovered by NASA’s Kepler mission. Since its launch in 2009, the Kepler satellite has detected 2,326 candidate planets, including the first “Tatooine” systems with planets orbiting double stars, and the first rocky planets within the “Goldilocks” zone where liquid water can exist. It is now estimated that at least 5.4% of all stars host Earth-size planets. The Museum asked Holorad to produce an immersive glasses-free holographic experience to illustrate Kepler’s findings as the finale of its special exhibition Beyond Planet Earth — The Future of Space Exploration. This hologram displays a real image with visual accommodation, so museum visitors can reach in to “touch” each star, and is full-parallax, so the starfield can be viewed by school groups including adults and children. We use proprietary techniques to produce holograms from sequential exposures of multi-slice data; this capability was originally developed for surgical planning using hundreds of CT and MR slices, and has now been extended to produce holograms from arbitrary three-dimensional data for advertising, entertainment, and education. For the Kepler data we developed software to map sky coordinates into X/Y, with the Z-axis mapped to the estimated distances of each star. For replay in the Museum we use an enclosed folded optical path, with the light-engine from a laser-television. The hologram is assembled from multiple abutting “tiles” laminated on to a large acrylic sheet, sandwiched with light control film for eye-safety and to conceal the illumination optics.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:07 River Valley TV English 2012

Computer holography: 3D digital art based on high-definition CGH

Recently, we presented some high-definition full-parallax CGHs calculated by our polygon-based method and fabricated by laser lithography system. These holograms, composed of more than billions pixels, produce very fine spatial 3D images of occluded virtual scenes and objects. The optically reconstructed images are comparable to that in classical holography. Strong sensation of depth caused by these high-definition CGHs has never been achieved by conventional 3D systems and pictures other than holography. In addition, we have also presented a new technique called “digitized holography.” In this technique, fringe caused by interference between a real existing object wave and reference wave is digitally recorded with wide area and high sampling density by using image sensors. The recorded object wave is incorporated in a virtual 3D scene constructed of CG-like 2D and 3D objects, and then, the virtual scene that keeps proper occluded relation is optically reconstructed by the technique of CGHs. This technique make it possible to digitally edit holograms after recording and will open the world of a novel digital art, referred to as Computer Holography. Various source materials can be input data in computer holography, for example, digital photos, illustrations, polygon-mesh 3D objects, multi-viewpoints images and captured fields of real existing objects. The 3D scene including these materials is designed employing a field-based digital-editing technique and optically reconstructed by the CGH technique as designers intend. We will present details of the technique as well as the concept of the computer holography. Furthermore, some of our works in computer holography will be demonstrated in the meeting.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
18:57 River Valley TV English 2012

Challenges in using GPU for the real-time reconstruction of digital hologram images

In-line holography has recently made the transition from silver-halide based recording media, with laser reconstruction, to recording with large-area pixel detectors and computer-based reconstruction. This form of holographic imaging is an established technique for the study of fine particulates, such as cloud or fuel droplets, marine plankton and alluvial sediments, and enables a true 3D object field to be recorded at high resolution over a considerable depth. The move to digital holography promises rapid, if not instantaneous, feedback as it avoids the need for the time-consuming chemical development of plates or film film and a dedicated replay system, but with the growing use of video-rate holographic recording, and the desire to reconstruct fully every frame, the computational challenge becomes considerable. To replay a digital hologram a 2D FFT must be calculated for every depth slice desired in the replayed image volume. A typical hologram of ~100 micrometre particles over a depth of a few hundred millimetres will require (10^3) 2D FFT operations to be performed on a hologram of typically a few million pixels. In this paper we discuss the technical challenges in converting our existing reconstruction code to make efficient use of NVIDIA CUDA-based GPU cards and show how near real-time video slice reconstruction can be obtained with holograms as large as 4096 by 4096 pixels. Our performance to date for a number of different NVIDIA GPU running under both Linux and Microsoft Windows is presented. We consider the implications for grid and cloud computing, and the extent to which GPU can replace these approaches, when the important step of locating focussed objects within a reconstructed volume is included.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:23 River Valley TV English 2012

Computational hologram synthesis and representation on SLM for real-time 3D holographic imaging

In dynamic computer-generated holography that utilizes spatial light modulators, both hologram synthesis and hologram representation is essential in terms of fast computation and high reconstruction quality. For hologram synthesis, i.e. the computation step, Fresnel transform based or point-source based raytracing methods can be applied. In the encoding step, the complex wave-field has to be optimally represented by the SLM with its given modulation capability. For proper hologram reconstruction that implies a simultaneous and independent amplitude and phase modulation of the input wave-field by the SLM. In this paper, we discuss full complex hologram representation methods on SLMs by considering inherent SLM parameter such as modulation type, fill factor, and bit depth on their reconstruction performance such as diffraction efficiency and SNR. We review the three implementation schemes of Burckhardt amplitude-only representation, phase-only macro-pixel representation, and two-phase interference representation. Besides the optical performance we address their hardware complexity and required computational load. Finally, we experimentally demonstrate holographic reconstructions of different representation schemes as obtained by functional prototypes utilizing SeeReal’s viewing-window holographic display technology. The proposed hardware implementations enable a fast encoding of complex-valued hologram data and thus will pave the way for commercial real-time holographic 3D imaging in the near future.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:59 River Valley TV English 2012

Coexistence

This paper is to introduce both a construction method for a Cylindrical Hologram and a work world of Ray’s Cylindrical Hologram through research about coexistence of between visible world and invisible world, since the first work, in 2007. ‘Green Apple’ of the Cylindrical Hologram, was issued, then a broad range of Cylindrical Hologram works have been completed following an improvement of a weak point that it is impossible to observe a portion of shadow occurred by a illumination in the construction of the previous Cylindrical Hologram. The Hologram works based on theme “coexistence of visible world and invisible world” has been exhibited four time in Korea between year 2011-2012. In addition, during the exhibition, works done by KETI using Holographic printer will be introduced as well. “I do hologram works. I work over and over for making false images through holograms with familiar, everyday, and current objects and photographs. It is the work process of a hologram that reappearances things and grants them permanence in terms of sustaining them. The world of wave is part of the world of invisible. It is not visible of sound wave, brain wave, and wavelength. Therefore it is clear that we live in coexistence of visible as well as invisible world. From the Theory of relativity by Einstein, it could be acknowledged that the visible is relative to the invisible. Through the quantum theory, exemplified by the story of Schrödinger’s cat, it could be resulted according to imagination or observation before watching outcomes from experiments. What we can interpret through this story is that things can be taken off as we imagine and the false image of hologram coexists in the visible “life”.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:23 River Valley TV English 2012

A new type of coupled wave theory capable of analytically describing diffraction in polychromatic gratings and holograms

A new type of coupled wave theory is described which is capable, in a very natural way, of analytically describing polychromatic gratings. In contrast to the well known and extremely successful coupled wave theory of Kogelnik, the new theory is based on a differential formulation of the process of Fresnel reflection within the grating. The fundamental coupled wave equations, which are an exact solution of Maxwell’s equations for the case of the unslanted reflection grating, can be analytically solved with minimal approximation. The equations may also be solved in a rotated frame of reference to provide useful formulae for the diffractive efficiency of the general polychromatic slanted grating in three dimensions. The new theory is compared with Kogelnik’s theory where extremely good agreement is found for most cases. The theory has also been compared to a rigorous computational chain matrix simulation of the unslanted grating with excellent agreement for cases typical to display holography. In contrast, Kogelnik’s theory shows small discrepancies away from Bragg resonance. The new coupled wave theory may easily be extended to an N-coupled wave theory for the case of the multiplexed polychromatic grating and indeed for the purposes of analytically describing diffraction in the colour hologram. In the simple case of a monochromatic multiplexed grating at Bragg resonance the theory is in exact agreement with the predictions of conventional N-coupled wave theory.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:03 River Valley TV English 2012

Content metamorphosis in synthetic holography

A synthetic hologram is an optical system made of hundreds of images amalgamated in a structure of holographic cells. Each of these images represents a point of view on a three-dimensional space which makes us consider synthetic holography as a multiple points of view perspective system. In the composition of a computer graphics scene for a synthetic hologram, the field of view of the holographic image can be divided into several viewing zones. We can attribute these divisions to any object or image feature independently and operate different transformations on image content. In computer generated holography, we tend to consider content variations as a continuous animation much like a short movie. However, by composing sequential variations of image features in relation with spatial divisions, we can build new narrative forms distinct from linear cinematographic narration. When observers move freely and change their viewing positions, they travel from one field of view division to another. In synthetic holography, metamorphoses of image content are within the observer’s path. In all imaging Medias, the transformation of image features in synchronisation with the observer’s position is a rare occurrence. However, this is a predominant characteristic of synthetic holography. This paper describes some of my experimental works in the development of metamorphic holographic images.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
17:10 River Valley TV English 2012

Calculation method of CGH for binocular eyepiece-type electro holography

We had researched about Eyepiece-type electro holography to display 3-D images of larger objects at wider angles. With Fourier optical system using two lenses, we had enlarged visual field considering depth of object. The purpose of the previous study is making a HMD (head-mount-display) for electro holography. And the HMD needs to have two displays for the left and right eye of a man. So, we have needed to extend our system for binocular. In binocular system, we needs to use two different hologram for each of eyes. The 3-D image reconstructed from each hologram is not the same; the 3-D image for left eye needs to be just like the real object observed using left eye, and the 3-D image for right eye needs to be so. In this paper, we propose a method of calculation of CGH transforming the coordinate system of the model data to make two holograms for binocular eyepiece-type electro holography. The coordinate system of original model data is called the world coordinate system. And the coordinate system of the model data used to make holograms for left and right eye are called the left eye coordinate system and the right eye coordinate system. The left and right coordinate system is made by using coordinate transformation from the world coordinate system. And in each coordinate system, the model data is corrected to remove distortion, and made to each hologram. Finally, the 3-D image reconstructed from two holograms is enlarged using two Fourier lenses just like a microscope. Optical reconstructed experiments were carried out. The results of experiments show the potential of the proposed method for the possibility of implementation of the HMD.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
22:14 River Valley TV English 2012

Commercial display holography: a history of failure?

Full parallax, full colour display holograms are regarded by most holographers as the ultimate in holography – and the ultimate in illustration and representation of the world. Everyone who sees a high quality display hologram is impressed – awestruck even. The recent revival of mega-shows of display holograms demonstrate this public fascination with and response to holograms. So why has it proved so difficult to produce these holograms successfully in a commercial context? Why have so many companies which were established to make and market display holograms succeeded at the making but failed in the marketing. Or more specifically, failed in the selling. Why don’t display holograms sell in commercially viable quantities? In this paper I will give a history of companies producing display holograms with commercial intent, showing that the successes are heavily outnumbered by the failures. I will examine the factors which appear to influence this history, from the holograms and the business side. And I will try to propose a route to success for the future by drawing out the lessons from the successes and the failures and examining what it takes to establish and survive as a business in the field of display holography. As the founder and original CEO of an initially successful but ultimately failed display hologram producer company, the editor of Holography News® for over 20 years, and the holder of a post-graduate business qualification, I hope I will bring a valuable perspective and insight to this topic.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:03 River Valley TV English 2012

Depth of field analysis for multilayer automultiscopic displays

With the reemergence of stereoscopic displays, through polarized glasses for theatrical presentations and shuttered liquid crystal eyewear in the home, automultiscopic displays have received increased attenuation. Commercial efforts have predominantly focused on parallax barrier and lenticular architectures applied to LCD panels. Such designs suffer from reduced resolution and brightness. Recently, multilayer LCDs have emerged as a design alternative supporting full-resolution imagery with enhanced brightness and depth of field. In this paper we introduce a single processing framework for comparing the depth of field for conventional and emerging automultiscopic LCD displays. We derive an upper bound for all such displays, encompassing prior depth of field expressions for parallax barriers and integral imaging, while indicating the significant potential of multilayer configurations.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
21:28 River Valley TV English 2012

New recording material with AgBr nanoparticles for optical holography

A new recording material with silver halide (AgBr) nanoparticles and photopolymerization system will be presented. It is well known that redistribution of silver halide particles within a gelatin layer is the main cause of a phase hologram formation in silver halide emulsions (SHE). Holograms recorded in SHE reach high value of the refractive index modulation as the difference between refractive indexes of AgBr and gelatin is relatively high. However, the AgBr nanoparticles in SHE may increase in their size during the wet chemical developing and rehalogenization processes. So when the SHE hologram is reconstructed, it appears noisy as the size of scattering particles grew up. Recently, we have developed a new self-developing recording medium with AgBr nanoparticles. It is composed of the gelatin binder with AgBr nanoparticles to which a photopolymerization system is added. During the holographic exposure, the radical chain polymerization process is initiated in the bright regions and polymer chains grow. As a consequence of the local polymerization process, the nanoparticles are excluded from polymerization regions and migrate to the surroundings where the local refractive index is growing up. The final result of nanoparticles distribution is the same as in the case of the processed SHE, but the AgBr nanoparticles in the gelatin layer preserve their original size as they don not undergo any chemical reactions. In our laboratory, the AgBr nanoparticles in gelatin sol are prepared by the method of chemical precipitation. Typically, the diameter of particles is about 30 nm and they have relatively narrow size distribution. The gelatin with nanoparticles is a basis for making of both SHE and photopolymer with nanoparticles, but different additives are used for respective materials. We have studied the recording processes with proper detection methods which lead to the redistribution of AgBr particles within the recording layer. In the paper, we will give the main results of our findings and also some properties of the new self-developing photopolymer with nanoparticles will be presented.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
18:45 River Valley TV English 2012

Hololujah: a one kilometre art hologram

This paper will outline the production of the white light transmission achromatic image hologram titled Hololujah measuring 3.5cm x 1 kilometre. The theme of this artwork is a comment on social networking sites such as Twitter. The paper will cover my use of Slavich VRP-M film measuring 1.14 x 30 metres that was exposed and processed as a complete roll in thirty individual metre sections. When finished the roll of film was cut into thirty-four 3.5cm x 30 metre strips with their ends cold laminated together to form the kilometre length hologram. The paper will expand on my use of a Coherent Compass 315M, 532nm, 150mW laser diode in a lenseless setup, using a single beam through diffuse glass, no isolation systems and two minute exposure times with the film lying flat on the floor. Lastly, I will illustrate how the hologram was produced in the 2×2x2.5 metre confined area of my bedroom.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
18:50 River Valley TV English 2012

LightLeaves: landscape reflection hologram installation with computer controlled lighting

LightLeaves is a wall-mounted installation of six panels of white light reflection, leaf shaped holograms, containing landscape imagery .The holograms are attached to the panels at different depths, and the illumination for the holograms is controlled by a specifically designed housing device, above and in front of the work, containing mirrors and movable light blocking leaf shaped masks. The housing device also holds a compact VEX robotic microprocessor controller, programmed to operate two motors, and temperature sensors, to control the movements of the light blocking masks, as the temperature in the space changes, simulating wind effects of sun light on leaves in trees. LightLeaves was first exhibited from June 2010 to June 2011 at the Peabody Essex Museum, in Salem, Massachusetts, in the show titled EYE SPY, Playing with Perception.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
19:05 River Valley TV English 2012

New education system for construction of optical holography setup

In case of teaching optical system construction, it is difficult to prepare the optical components for the attendance student. However the tangible learning is very important to master the optical system construction. Developing the inexpensive system which provide the experience learning helps learner understand easily. Therefore, we propose the new education system for construction of optical setup with the augmented reality. To use the augmented reality, the proposed system can simulate the optical system construction by the direct hand control. Also, this system only requires a inexpensive web camera, printed makers and a personal computer. Since this system does not require the darkroom and the expensive optical equipments, the learner can study anytime, anywhere when they want to do.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
20:43 River Valley TV English 2012

Modular subwavelength diffractive light modulator for high-definition holographic displays

Holography is undoubtedly the ultimate 3D visualization technology, offering true 3D experience with all the natural depth cues, without the undesirable side-effects of current stereoscopic systems (uncomfortable glasses, strained eyes, fatiguing experience). Realization of a high-definition holographic display however requires a number of breakthroughs from existing prototypes. One of the main challenges lies in technology scaling, as holography is based on light diffraction and interference – to achieve wide viewing angles, the light-modulating pixels need to be spaced close to or below the wavelength of the used visible light. Furthermore, achieving high 3D image quality, hundreds of millions of such individually programmable pixels are needed.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
22:39 River Valley TV English 2012

Holography without frames: sculptural installations incorporating ʻdrawnʼ elements

Since its adoption by artists, shortly after the process became practical in the 1960’s, holography has struggled to be accepted as a legitimate medium within the visual arts. A number of key milestones, during the early developmental process of creative holography, are acknowledged with reference to sparse but significant critical discussions. The value of ‘traditional’, framed, wall-based display is explored and a number of sculptural installations by the author, which have attempted to question this method of presentation, are discussed. Floor-based installations, which involve the integration of drawn holographic elements within site-specific locations, are examined.
  • Published: 2012
  • Publisher: River Valley TV
  • Language: English
out of 2 pages
Loading...
Feedback

Timings

  127 ms - page object
   32 ms - search
    1 ms - highlighting
    0 ms - highlighting/21035
    0 ms - highlighting/21042
    0 ms - highlighting/21027
    0 ms - highlighting/21052
    0 ms - highlighting/21038
    0 ms - highlighting/21022
    0 ms - highlighting/21044
    0 ms - highlighting/21033
    0 ms - highlighting/21020
    0 ms - highlighting/21039
    0 ms - highlighting/21034
    0 ms - highlighting/21032
    0 ms - highlighting/21051
    0 ms - highlighting/21055
    0 ms - highlighting/21018
    0 ms - highlighting/21040
    0 ms - highlighting/21041
    0 ms - highlighting/21046
    0 ms - highlighting/21031
    0 ms - highlighting/21036
    0 ms - highlighting/21026
    0 ms - highlighting/21019
    0 ms - highlighting/21024
    0 ms - highlighting/21054
    0 ms - highlighting/21053
    0 ms - highlighting/21050
    0 ms - highlighting/21047
    0 ms - highlighting/21048
    0 ms - highlighting/21043
    1 ms - highlighting/21045
    1 ms - highlighting/21030
    1 ms - highlighting/21028
    1 ms - highlighting/21023
    1 ms - highlighting/21029
    0 ms - highlighting/21021
    0 ms - highlighting/21037

Version

AV-Portal 3.8.2 (0bb840d79881f4e1b2f2d6f66c37060441d4bb2e)