Search Results (50)

This paper starts with an overview of current methods of displaying 3D objects. Two different technologies are compared—a glasses-free 3D laptop that uses stereoscopy, and one that uses front projection on a silver impregnated fabric screen that diffracts light to achieve a holographic effect. The research question is defined—which one is suitable for use by specialists. A methodology for an experiment is designed. A scenario for finding the solution to the problem during the experiment is created. An experiment environment with different workstations for each technology has been set up. An additional reference workstation with a standard screen has been created. Three-dimensional CAD models from the field of mechanical engineering were chosen. Different categories of defects were introduced to make the models usable for the scenario—finding the defects in each of the different workstations. A survey for participant feedback, using several categories of questions, was created, improved, and used during the experiment. The experiment was completed, short discussions were held with each participant, and their feedback was analyzed. The categories of the participants were discussed. The results from the experiment were discussed and analyzed. Statistical analysis was performed on the survey results. The applicability of the experiment in other fields was discussed. Conclusions were made, and the comparative advantages and specifics of each technology were discussed based on the analysis results and the experience gained during the experiment. Full article

Interference gating (iGate) has emerged as a groundbreaking technique for ultrafast time-resolved electron holography in transmission electron microscopy, delivering nanometer spatial and nanosecond temporal resolution with minimal technological overhead. This study employs iGate to dynamically observe the local projected electric potential within the space-charge region of a contacted transmission electron microscopy (TEM) lamella manufactured from a silicon diode during switching between unbiased and reverse-biased conditions, achieving a temporal resolution of 25 ns at a repetition rate of 3 MHz. By synchronizing the holographic acquisition with the applied voltage, this approach enables the direct visualization of time-dependent potential distributions with high precision. Complementary static and dynamic experiments reveal a remarkable correspondence between modeled and measured projected potentials, validating the method’s robustness. The observed dynamic phase progressions resolve and allow one to differentiate between localized switching dynamics and preparation-induced effects, such as charge recombination near the sample edges. These results establish iGate as a transformative tool for operando investigations of semiconductor devices, paving the way for advancing the nanoscale imaging of high-speed electronic processes. Full article

Augmented reality technologies provide transformative solutions in various surgical fields. Our research focuses on the use of an advanced augmented reality system that projects 3D holographic images directly into surgical footage, potentially improving the surgeon’s orientation to the surgical field and lowering the cognitive load. We created a novel system that combines exoscopic surgical footage from the “ORBEYE” and displays both the surgical field and 3D holograms on a single screen. This setup enables surgeons to use the system without using head-mounted displays, instead viewing the integrated images on a 3D monitor. Thirteen surgeons and surgical assistants completed tasks with 2D and 3D graphical surgical guides. The NASA Task Load Index was used to assess mental, physical, and temporal demands. The use of 3D graphical surgical guides significantly improved performance metrics in cochlear implant surgeries by lowering mental, physical, temporal, and frustration levels. However, for Bonebridge implantation, the 2D graphical surgical guide performed better overall (p = 0.045). Participants found the augmented reality system’s video latency to be imperceptible, measuring 0.13 ± 0.01 s. This advanced augmented reality system significantly improves the efficiency and precision of cochlear implant surgeries by lowering cognitive load and improving spatial orientation. Full article

Guangdong puppetry, a 700-year-old intangible cultural heritage, faces declining popularity due to economic influences and evolving youth interests. The shrinking audience and a lack of successors to inherit this tradition further compound the issue. This research aims to revitalize the puppet show by preserving its traditional roots, exploring new possibilities, and engaging the younger generation. Divided into three stages—preliminary investigation, role modeling, and holographic projection device design—the study utilizes field research, literature review, questionnaires, and experiments. Information is gathered through venue visits, which is followed by questionnaire distribution and 3D model creation based on survey results. The final stage involves designing and testing a holographic projection booth. Full article

The development of science and technology constantly injects new vitality into dance performance and creation. Among them, three-dimensional (3D) vision technology provides novel ideas for the innovation and artistry of dance performances, expands the forms of dance performances and the way to present dance works, and brings a brand-new viewing experience to the audience. Nowadays, 3D vision technology in dance has been widely researched and applied. This review presents the background of the 3D vision technology application in the dance field, analyzes the main types of technology and working principles for realizing 3D vision, summarizes the research and application of the 3D vision technology in dance creation, perception, enhancement, and dance teaching, and finally looks forward to the development prospect of the 3D vision technology in the dance. Full article

Discovered as an apparent pattern, a universal relation between geometry and information called the holographic principle has yet to be explained. This relation is unfolded in the present paper. As it is demonstrated there, the origin of the holographic principle lies in the fact that a geometry of physical space has only a finite number of points. Furthermore, it is shown that the puzzlement of the holographic principle can be explained by a magnification of grid cells used to discretize geometrical magnitudes such as areas and volumes into sets of points. To wit, when grid cells of the Planck scale are projected from the surface of the observable universe into its interior, they become enlarged. For that reason, the space inside the observable universe is described by the set of points whose cardinality is equal to the number of points that constitute the universe’s surface. Full article

Background: Three-dimensional reconstructions of state-of-the-art high-resolution imaging are progressively being used more for preprocedural assessment in thoracic surgery. It is a promising tool that aims to improve patient-specific treatment planning, for example, for minimally invasive or robotic-assisted lung resections. Increasingly available mixed-reality hardware based on video pass-through technology enables the projection of image data as a hologram onto the patient. We describe the novel method of real-time 3D surgical planning in a mixed-reality setting by presenting three representative cases utilizing volume rendering. Materials: A mixed-reality system was set up using a high-performance workstation running a video pass-through-based head-mounted display. Image data from computer tomography were imported and volume-rendered in real-time to be customized through live editing. The image-based hologram was projected onto the patient, highlighting the regions of interest. Results: Three oncological cases were selected to explore the potentials of the mixed-reality system. Two of them presented large tumor masses in the thoracic cavity, while a third case presented an unclear lesion of the chest wall. We aligned real-time rendered 3D holographic image data onto the patient allowing us to investigate the relationship between anatomical structures and their respective body position. Conclusions: The exploration of holographic overlay has proven to be promising in improving preprocedural surgical planning, particularly for complex oncological tasks in the thoracic surgical field. Further studies on outcome-related surgical planning and navigation should therefore be conducted. Ongoing technological progress of extended reality hardware and intelligent software features will most likely enhance applicability and the range of use in surgical fields within the near future. Full article

We demonstrate an experimental assessment of a high-Q, high-angle piezoelectric (2 µm PZT) MEMS scanning micromirror featuring distributed backside reinforcement, suitable for applications demanding energy-efficient and high-quality image projection. Frequency response measurements at 10 different vacuum levels ranging from atmospheric pressure to 10⁻⁶ mbar allow for the quantitative separation of damping mechanisms (air and structural). Stroboscopic digital holographic microscopy was used to assess the static and dynamic deformation of the mirror surface. The experimental results are in good agreement with simulations and models. Full article

This paper has proposed a full-color holography based on the space division method to provide a new solution for three-dimensional color holographic display. The hologram is divided into three different regions for the R, G, and B trichromatic hologram components, which will be designed separately at the corresponding positions. The projection images at different projection depths are preprocessed to meet dimension matching and position matching conditions. Different color images are reconstructed on a single plane and 19 planes in simulations and experiments, respectively, which verify the feasibility of the method. The designed phase-only holograms were fabricated on the silica substrate to obtain the diffraction optical element (DOE). Expect for one DOE, three lasers, and one CCD, no additional optical components are required to prompt a compact and simple experimental setup, which is expected to be used to realize full-color display. Full article

A super multi-view (SMV) near-eye display (NED) effectively provides depth cues for three-dimensional (3D) display by projecting multiple viewpoint or parallax images onto the retina simultaneously. Previous SMV NED have suffered from a limited depth of field (DOF) due to a fixed image plane. In this paper, a holographic SMV Maxwellian display based on depth segmentation is proposed to enhance the DOF. The proposed approach involves capturing a set of parallax images and their corresponding depth maps. According to the depth maps, the parallax images are segmented into N sub-parallax images at different depth ranges. These sub-parallax images are then projected onto N image-recording planes (IRPs) of the corresponding depth for hologram computation. The wavefront at each IRP is calculated by multiplying the sub-parallax images with the corresponding spherical wave phases. Then, they are propagated to the hologram plane and added together to form a DOF-enhanced hologram. The simulation and experimental results are obtained to validate the effectiveness of the proposed method in extending the DOF of the holographic SMV displays, while accurately preserving occlusion. Full article

Ancient manuscripts are precious and fragile objects, preserved in libraries, museums, and archives. Some of them are masterpieces, made with several materials and insights, but generally they are not accessible to wide communities of users. The purpose of this study is to present the preliminary results of the Codex4D project: a holographic showcase, conceived for museums, presenting the first 4D model of an ancient manuscript to the public at the Science Festival in Genoa in 2022. The manuscript, preserved in the Angelica Library in Rome, has been represented in a multidimensional digital model, documenting both its visible and invisible aspects, on the surface and in the stratigraphic layers. We analysed the visitor experience: informal learning, the meaning-making process, interactions between visitors, and gesture-based interaction with the showcase. The methodology used for evaluation is based on four different qualitative methods (grounded theory, narrative inquiry, case study, and digital ethnography). We collected notes from observation, narratives from interviews, and answers from structured interviews. The main findings are patterns of the visitors’ experiences with a digital interactive 4D model of an ancient manuscript, supported by storytelling, and a list of design issues and possible improvements for the next version of the Codex4D holographic showcase. Full article

Mobile-health (m-health) is described as the application of medical sensors and mobile computing to the healthcare provision. While 5G networks can support a variety of m-health services, applications such as telesurgery, holographic communications, and augmented/virtual reality are already emphasizing their limitations. These limitations apply to both the Quality of Service (QoS) and the Quality of Experience (QoE). However, 6G mobile networks are predicted to proliferate over the next decade in order to solve these limitations, enabling high QoS and QoE. Currently, academia and industry are concentrating their efforts on the 6G network, which is expected to be the next major game-changer in the telecom industry and will significantly impact all other related verticals. The exponential growth of m-health multimedia traffic (e.g., audio, video, and images) creates additional challenges for service providers in delivering a suitable QoE to their customers. As QoS is insufficient to represent the expectations of m-health end-users, the QoE of the services is critical. In recent years, QoE has attracted considerable attention and has established itself as a critical component of network service and operation evaluation. This article aims to provide the first thorough survey on a promising research subject that exists at the intersection of two well-established domains, i.e., QoE and m-health, and is driven by the continuing efforts to define 6G. This survey, in particular, creates a link between these two seemingly distinct domains by identifying and discussing the role of 6G in m-health applications from a QoE viewpoint. We start by exploring the vital role of QoE in m-health multimedia transmission. Moreover, we examine how m-health and QoE have evolved over the cellular network’s generations and then shed light on several critical 6G technologies that are projected to enable future m-health services and improve QoE, including reconfigurable intelligent surfaces, extended radio communications, terahertz communications, enormous ultra-reliable and low-latency communications, and blockchain. In contrast to earlier survey papers on the subject, we present an in-depth assessment of the functions of 6G in a variety of anticipated m-health applications via QoE. Multiple 6G-enabled m-health multimedia applications are reviewed, and various use cases are illustrated to demonstrate how 6G-enabled m-health applications are transforming human life. Finally, we discuss some of the intriguing research challenges associated with burgeoning multimedia m-health applications. Full article

The super multi-view (SMV) near-eye display (NED) effectively provides depth cues for three-dimensional (3D) displays by projecting multiple viewpoint images or parallax images onto the retina simultaneously. Previous SMV NED suffers from a limited depth of field (DOF) due to the fixed image plane. Aperture filtering is widely used to enhance the DOF; however, an invariably sized aperture may have opposite effects on objects with different reconstruction depths. In this paper, a holographic SMV display based on the variable filter aperture is proposed to enhance the DOF. In parallax image acquisition, multiple groups of parallax images, each group recording a part of the 3D scene on a fixed depth range, are captured first. In the hologram calculation, each group of wavefronts at the image recording plane (IRP) is calculated by multiplying the parallax images with the corresponding spherical wave phase. Then, they are propagated to the pupil plane and multiplied by the corresponding aperture filter function. The size of the filter aperture is variable which is determined by the depth of the object. Finally, the complex amplitudes at the pupil plane are back-propagated to the holographic plane and added together to form the DOF-enhanced hologram. Simulation and experimental results verify the proposed method could improve the DOF of holographic SMV display, which will contribute to the application of 3D NED. Full article

Efficient vertical transportation is vital to a skyscraper’s functional operation and the convenience and satisfaction of its tenants. This review complements the author’s previously published research by updating the readers on innovative hardware and software-based solutions. It lays out, organizes, and combines extensive and scattered material on numerous aspects of elevator design in a straightforward and non-technical narrative. Rope-less elevators, the MULTI, artificial intelligence (AI), the Internet of Things (IoT), and extended reality technologies are some of the developments and advancements this article examines. The analysis also contextualizes current technical developments by reviewing how they are used in significant projects such as the One World Trade Center in New York City. Lastly, the paper examines innovative technologies, such as holographic elevator buttons and ultraviolet rays that disinfect elevators, in response to the COVID-19 pandemic. Full article

The subject of this investigation is light diffraction from a structure formed at the lateral projection of structured light on the surface of a 3D object. It is demonstrated that the patterns of vertically structured light fringes change their structure during the lateral illumination of a 3D object, and take on the properties of holograms. The diffraction of light from this structure forms several diffraction orders, and one of them can restore the image of the 3D object. Results of the numerical experiment demonstrating the possibility to restore 3D holographic images by these patterns at a wavelength corresponding to Bragg conditions are presented. The obtained result allows an order of magnitude higher compression of the holographic information about a 3D object to be transmitted along the communication channel, in a volume that is sufficient for visual perception, and for the observation of both the horizontal and vertical continuous parallax. Results of the experiments on the transmission of this compressed information are presented to demonstrate that the TV frame rate frequency of the 3D holographic video sequence is quite achievable. Full article