scholarly journals Implementation of the real–virtual 3D scene-fused full-parallax holographic stereogram

2021 ◽  
Author(s):  
Xingpeng Yan ◽  
Chenqing Wang ◽  
Yunpeng Liu ◽  
Xi Wang ◽  
xinlei liu ◽  
...  
Keyword(s):  
The Real ◽  
Holographic Stereogram ◽  
3D Scene

scholarly journals Fusion Coding of 3D Real and Virtual Scenes Information for Augmented Reality-Based Holographic Stereogram

2021 ◽  
Vol 9 ◽  
Author(s):  
Yunpeng Liu ◽  
Xingpeng Yan ◽  
Xinlei Liu ◽  
Xi Wang ◽  
Tao Jing ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Three Dimensional ◽  
Depth Map ◽  
Depth Information ◽  
Sampling System ◽  
The Real ◽  
Coding Method ◽  
Holographic Stereogram ◽  
3D Scene ◽  
Instance Segmentation

In this paper, an optical field coding method for the fusion of real and virtual scenes is proposed to implement an augmented reality (AR)-based holographic stereogram. The occlusion relationship between the real and virtual scenes is analyzed, and a fusion strategy based on instance segmentation and depth determination is proposed. A real three-dimensional (3D) scene sampling system is built, and the foreground contour of the sampled perspective image is extracted by the Mask R-CNN instance segmentation algorithm. The virtual 3D scene is rendered by a computer to obtain the virtual sampled images as well as their depth maps. According to the occlusion relation of the fusion scenes, the pseudo-depth map of the real scene is derived, and the fusion coding of 3D real and virtual scenes information is implemented by the depth information comparison. The optical experiment indicates that AR-based holographic stereogram fabricated by our coding method can reconstruct real and virtual fused 3D scenes with correct occlusion and depth cues on full parallax.

scholarly journals Attention-Based Multi-Modal Fusion Network for Semantic Scene Completion

2020 ◽  
Vol 34 (07) ◽  
pp. 11402-11409
Author(s):  
Siqi Li ◽  
Changqing Zou ◽  
Yipeng Li ◽  
Xibin Zhao ◽  
Yue Gao
Keyword(s):  
State Of The Art ◽  
Semantic Segmentation ◽  
Spatial Dimension ◽  
Semantic Features ◽  
Convolutional Network ◽  
The Real ◽  
Single View ◽  
Depth Cues ◽  
Semantic Scene ◽  
3D Scene

This paper presents an end-to-end 3D convolutional network named attention-based multi-modal fusion network (AMFNet) for the semantic scene completion (SSC) task of inferring the occupancy and semantic labels of a volumetric 3D scene from single-view RGB-D images. Compared with previous methods which use only the semantic features extracted from RGB-D images, the proposed AMFNet learns to perform effective 3D scene completion and semantic segmentation simultaneously via leveraging the experience of inferring 2D semantic segmentation from RGB-D images as well as the reliable depth cues in spatial dimension. It is achieved by employing a multi-modal fusion architecture boosted from 2D semantic segmentation and a 3D semantic completion network empowered by residual attention blocks. We validate our method on both the synthetic SUNCG-RGBD dataset and the real NYUv2 dataset and the results show that our method respectively achieves the gains of 2.5% and 2.6% on the synthetic SUNCG-RGBD dataset and the real NYUv2 dataset against the state-of-the-art method.

scholarly journals Efficient Hogel-Based Hologram Synthesis Method for Holographic Stereogram Printing

2020 ◽  
Vol 10 (22) ◽  
pp. 8088
Author(s):  
Erkhembaatar Dashdavaa ◽  
Anar Khuderchuluun ◽  
Hui-Ying Wu ◽  
Young-Tae Lim ◽  
Chang-Won Shin ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Spatial Resolution ◽  
Angular Resolution ◽  
Synthesis Method ◽  
Three Dimensional ◽  
Lateral Resolution ◽  
Trade Off ◽  
Optical Experiment ◽  
Holographic Stereogram ◽  
3D Scene

With the development of the holographic printer, printing synthetic hologram requires smaller holographic element (hogel) size to improve spatial resolution of the reconstruction. On the contrary, a larger hogel size affords higher angular resolution, but it leads to a lower lateral resolution and there exists a trade-off problem. In this paper, a hologram synthesis method based on three-dimensional (3D) rendering of computer-generated holographic stereogram (HS) is proposed to limit the spatial-angular trade-off problem. The perspectives of the 3D scene are captured by re-centering the camera method and transformed into parallax-related images by a proposed pixel re-arrangement algorithm for holographic printing. Unlike the conventional approaches, the proposed algorithm not only improves the angular resolution of the reconstruction while maintaining the hogel size fixed, but also keeps the spatial resolution without degradation. The effectiveness of the proposed method is verified by numerical simulation and an optical experiment.

Research on Scene Organize Algorithm Based on BVH with Dynamic Rendering Tree

2014 ◽  
Vol 596 ◽  
pp. 370-373
Author(s):  
Li Xu ◽  
Mao Zhen Liu
Keyword(s):  
Real Time ◽  
Collision Detection ◽  
Visual Effect ◽  
The Real ◽  
Scale Factors ◽  
Bounding Volume ◽  
Scene Management ◽  
Tree Construction ◽  
3D Scene ◽  
Bounding Volume Hierarchy

: The real-time rendering of 3D scene need excellent algorithm to support scene management. After considering the algorithm complexity and scene scale factors, combining the advantages of Bounding Volume Hierarchy (BVH) and rendering tree in scene management, this paper puts forward a kind of scene organize algorithm, to solve the problem of render states redundant calculation when using BVH technology to solve the problem of deformable collision detection, by choosing the appropriate strategy of Hierarchy Bounding Volume tree construction and optimizing rendering tree of the scene. Experiments prove the proposed algorithm can effectively improve the rendering efficiency of 3D scene, enhance the visual effect.

scholarly journals Multi-Shape Free-Form Deformation Framework for Efficient Data Transmission in AR-Based Medical Training Simulators

2021 ◽  
Vol 11 (21) ◽  
pp. 9925
Author(s):  
Myeongjin Kim ◽  
Fernando Bello
Keyword(s):  
Real World ◽  
Medical Training ◽  
Free Form ◽  
Control Points ◽  
Surface Mesh ◽  
The Real ◽  
Free Form Deformation ◽  
Simulation Scenario ◽  
3D Scene ◽  
Global Deformation

Augmented reality medical training simulators can provide a realistic and immersive experience by overlapping the virtual scene on to the real world. Latency in augmented reality (AR) medical training simulators is an important issue as it can lead to motion sickness for users. This paper proposes a framework that can achieve real-time rendering of the 3D scene aligned to the real world using a head-mounted display (HMD). Model deformation in the 3D scene is categorised into local deformation derived from user interaction and global deformation determined by the simulation scenario. Target shapes are predefined by a simulation scenario, and control points are placed to embed the predefined shapes. Free-form deformation (FFD) is applied to multiple shapes to efficiently transfer the simulated model to the HMD. Global deformation is computed by blending a mapping matrix of each FFD with an assigned weighting value. The local and global deformation are then transferred through the control points updated from a deformed surface mesh and its corresponding weighting value. The proposed framework is verified in terms of latency caused by data transmission and the accuracy of a transmitted surface mesh in a vaginal examination (VE) training simulation. The average latency is reduced to 7 ms, less than the latency causing motion sickness in virtual reality simulations. The maximum relative error is less than 3%. Our framework allows seamless rendering of a virtual scene to the real world with substantially reduced latency and without the need for an external tracking system.

scholarly journals Augmented reality using holographic display

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Hung-Chun Lin ◽  
Yung-Hsun Wu
Keyword(s):  
Image Quality ◽  
Augmented Reality ◽  
Depth Information ◽  
Viewing Angle ◽  
Virtual Image ◽  
The Real ◽  
Holographic Display ◽  
Extra Information ◽  
Wide Viewing Angle ◽  
3D Scene

AbstractAugmented reality (AR) provided extra information to the user by applying virtual image onto the real environment. There are many methods achieving AR. Holographic display is one of the potential ways due to its perfect 3D demonstration. Holographic display can provide the virtual 3D object with depth information. It can be realized an AR device with real 3D scene by combing holographic display. However, it is difficult to realize a compact holographic display with wide viewing angle and enough resolution. It limits holographic display to apply to AR. In this paper, we will discuss the requirements of holographic display based on the development of LCD, including resolution (ppi), viewing angle, image quality and backlight. We wish this article can provide preliminary direction for the LCD industry to develop AR technology using holographic display.

Scanning electron microscopy of human iliac bone by a simple preparation method

1990 ◽  
Vol 48 (3) ◽  
pp. 226-227
Author(s):  
Toshihiko Takita ◽  
Tomonori Naguro ◽  
Toshio Kameie ◽  
Akihiro Iino ◽  
Kichizo Yamamoto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Real Surface ◽  
Public Attention ◽  
Preparation Methods ◽  
The Real ◽  
Simple Preparation ◽  
Scanning Electron

Recently with the increase in advanced age population, the osteoporosis becomes the object of public attention in the field of orthopedics. The surface topography of the bone by scanning electron microscopy (SEM) is one of the most useful means to study the bone metabolism, that is considered to make clear the mechanism of the osteoporosis. Until today many specimen preparation methods for SEM have been reported. They are roughly classified into two; the anorganic preparation and the simple preparation. The former is suitable for observing mineralization, but has the demerit that the real surface of the bone can not be observed and, moreover, the samples prepared by this method are extremely fragile especially in the case of osteoporosis. On the other hand, the latter has the merit that the real information of the bone surface can be obtained, though it is difficult to recognize the functional situation of the bone.

Personal Audio System: Hearing Symptoms, Habits, and Sound Pressure Levels Measured in Real Ear and a Manikin

2020 ◽  
Vol 63 (6) ◽  
pp. 2016-2026
Author(s):  
Tamara R. Almeida ◽  
Clayton H. Rocha ◽  
Camila M. Rabelo ◽  
Raquel F. Gomes ◽  
Ivone F. Neves-Lobo ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Daily Basis ◽  
Cross Sectional Study ◽  
Normal Hearing ◽  
Chi Square ◽  
Cross Sectional ◽  
The Real ◽  
Significant Difference ◽  
Sound Pressure Levels ◽  
Audio System

Purpose The aims of this study were to characterize hearing symptoms, habits, and sound pressure levels (SPLs) of personal audio system (PAS) used by young adults; estimate the risk of developing hearing loss and assess whether instructions given to users led to behavioral changes; and propose recommendations for PAS users. Method A cross-sectional study was performed in 50 subjects with normal hearing. Procedures included questionnaire and measurement of PAS SPLs (real ear and manikin) through the users' own headphones and devices while they listened to four songs. After 1 year, 30 subjects answered questions about their usage habits. For the statistical analysis, one-way analysis of variance, Tukey's post hoc test, Lin and Spearman coefficients, the chi-square test, and logistic regression were used. Results Most subjects listened to music every day, usually in noisy environments. Sixty percent of the subjects reported hearing symptoms after using a PAS. Substantial variability in the equivalent music listening level (Leq) was noted ( M = 84.7 dBA; min = 65.1 dBA, max = 97.5 dBA). A significant difference was found only in the 4-kHz band when comparing the real-ear and manikin techniques. Based on the Leq, 38% of the individuals exceeded the maximum daily time allowance. Comparison of the subjects according to the maximum allowed daily exposure time revealed a higher number of hearing complaints from people with greater exposure. After 1 year, 43% of the subjects reduced their usage time, and 70% reduced the volume. A volume not exceeding 80% was recommended, and at this volume, the maximum usage time should be 160 min. Conclusions The habit of listening to music at high intensities on a daily basis seems to cause hearing symptoms, even in individuals with normal hearing. The real-ear and manikin techniques produced similar results. Providing instructions on this topic combined with measuring PAS SPLs may be an appropriate strategy for raising the awareness of people who are at risk. Supplemental Material https://doi.org/10.23641/asha.12431435

Current Issues: Evidence-Based Practice for the Real World: Thoughts on Clinical Education in Communication Disorders

2010 ◽  
Vol 20 (3) ◽  
pp. 100-105 ◽  
Author(s):  
Anne K. Bothe
Keyword(s):  
Clinical Education ◽  
Real World ◽  
Evidence Based Practice ◽  
Communication Disorders ◽  
University Faculty ◽  
Evidence Based ◽  
Speech Language Pathology ◽  
Basic Principles ◽  
The Real ◽  
Language Pathology

This article presents some streamlined and intentionally oversimplified ideas about educating future communication disorders professionals to use some of the most basic principles of evidence-based practice. Working from a popular five-step approach, modifications are suggested that may make the ideas more accessible, and therefore more useful, for university faculty, other supervisors, and future professionals in speech-language pathology, audiology, and related fields.

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