3D Stereoscopic Display Research Articles

Fabrication of microlens arrays on curved substrates for large viewing angle integral imaging 3D display

Curved integral imaging for three-dimensional (3D) displays is well-known for offering an immersive experience and a wider display field of view. Presently, numerous techniques for fabricating curved microlens arrays (curved MLA) have been documented. Nevertheless, the majority of prior research relied on indirect approaches, like utilizing flexible substrates or creating molds. This paper introduces a method for directly fabricating microlens arrays (MLAs) on curved quartz glass. Well-designed arrays of controlled adhesive droplets were created on a hydrophilic-hydrophobic patterned surface. The resulting MLAs, manufactured on a curved substrate with a radius of 10 cm and dimensions of 5 cm × 5 cm, exhibit an 826.5 μm diameter, 56 μm inter-lens spacing, and a 4.5 mm focal length. The effective area of the curved MLA measures 45.8 mm × 45.8 mm. The study encompasses the design of a 2D elemental image and its integration with the curved MLA to achieve a compelling 3D display effect. The lateral viewing range is 2.2 cm. Notably, the field of view angle for the MLA, fabricated on a curved substrate, reached 11.2°, surpassing that of planar MLAs. The imaging system delivers an extensive field of view and attains a realistic 3D stereoscopic display effect. This method, employing various masks, facilitates the rapid fabrication of MLAs on substrates with diverse curvatures and sizes.

Pediatric patient-specific three-dimensional virtual models for surgical decision making in resection of hepatic and retroperitoneal tumors.

Typically, preoperative imaging is viewed in two dimensions (2D) only, but three-dimensional (3D) virtual models may improve viewers' anatomical perspective by permitting them to interact with the imaging through manipulating it in space. Research into the utility of these models in most surgical specialties is growing rapidly. This study investigates the utility of 3D virtual models of complex pediatric abdominal tumors for clinical decision making, particularly the decision to proceed with surgical resection or not. 3D virtual models of tumors and adjacent anatomy were created from CT images of pediatric patients scanned for Wilms tumor, neuroblastoma or hepatoblastoma. Pediatric surgeons individually assessed the resectability of the tumors. First, they assessed resectability using the standard protocol of viewing imaging on conventional screens and then reassessed resectability after being presented with the 3D virtual models. Inter-physician agreement on resectability for each patient was analyzed using Krippendorff's alpha. Inter-physician agreement was used as a surrogate for correct interpretation. Participants were also surveyed afterward on the utility and practicality of the 3D virtual models for clinical decision making. Inter-physician agreement when using CT imaging alone was "fair" (Krippendorff's alpha α = 0.399), while inter-physician agreement when using 3D virtual models increased to "moderate" (Krippendorff's alpha α = 0.532). When surveyed about model utility, all 5 participants considered them helpful. Two participants felt the models would be practical for clinical use in most cases, while 3 felt they would be practical for select cases only. This study demonstrates the subjective utility of 3D virtual models of pediatric abdominal tumors for clinical decision making. The models are an adjunct that can be particularly useful in complicated tumors that efface or displace critical structures that may impact resectability. Statistical analysis demonstrates the improved inter-rater agreement with the 3D stereoscopic display over the 2D display. The use of 3D displays of medical images will increase over time, and evaluation of their potential usefulness in various clinical settings is necessary.

Benefit of stereoscopic volume rendering for the identification of pediatric pulmonary vein stenosis from CT angiography.

The use of three-dimensional (3D) technologies in medical practice is increasing; however, its use is largely untested. One 3D technology, stereoscopic volume-rendered 3D display, can improve depth perception. Pulmonary vein stenosis (PVS) is a rare cardiovascular pathology, often diagnosed by computed tomography (CT), where volume rendering may be useful. Depth cues may be lost when volume rendered CT is displayed on regular screens instead of 3D displays. The objective of this study was to determine whether the 3D stereoscopic display of volume-rendered CT improved perception compared to standard monoscopic display, as measured by PVS diagnosis. CT angiograms (CTAs) from 18 pediatric patients aged 3 weeks to 2 years were volume rendered and displayed with and without stereoscopic display. Patients had 0 to 4 pulmonary vein stenoses. Participants viewed the CTAs in 2 groups with half on monoscopic and half on stereoscopic display and the converse a minimum of 2 weeks later, and their diagnoses were recorded. A total of 24 study participants, comprised of experienced staff cardiologists, cardiovascular surgeons and radiologists, and their trainees viewed the CTAs and assessed the presence and location of PVS. Cases were classified as simple (2 or fewer lesions) or complex (3 or more lesions). Overall, there were fewer type 2 errors in diagnosis for stereoscopic display than standard display, an insignificant difference (p = 0.095). There was a significant decrease in type 2 errors for complex multiple lesion cases (≥3) vs simpler cases (p = 0.027) and improvement in localization of pulmonary veins (p = 0.011). Subjectively, 70% of participants stated that stereoscopy was helpful in the identification of PVS. The stereoscopic display did not result in significantly decreased errors in PVS diagnosis but was helpful for more complex cases.

HiddenGazeStereo: Hiding Gaze-Contingent Disparity Remapping for 2D-Compatible Natural 3D Viewing

Stereoscopic 3D displays (S3D), the most popular consumer display devices for 3D presentation, have a few problems that degrade the natural visual experience, such as unnatural relationships between eye vergence and accommodation, and severe image blurring (ghost) for viewers without stereo glasses. To simultaneously solve these problems, we combine gaze-contingent disparity remapping with Hidden Stereo in a manner that mutually compensates for their respective shortcomings. Gaze-contingent disparity remapping can reduce the vergence-accommodation conflict by shifting the disparity distribution around the gaze position to be centered on the display plane. Hidden Stereo can synthesize 2D-compatible 3D stereo images that do not produce any ghosting artifacts when the images for the two eyes are linearly fused. Thus, by using our new gaze-contingent display, while one viewer with glasses enjoys natural 3D content, many other glassless viewers enjoy clear 2D content. To enable real-time synthesis, we accelerate Hidden Stereo conversion by limiting the processing to each horizontal scanline. Through a user study using a variety of 3D scenes, we demonstrate that Hidden Stereo can effectively hide disparity information to glassless viewers despite the dynamic disparity manipulations. Moreover, we show that our method can alleviate the limitation of Hidden Stereo—the narrow reproducible disparity range—by manipulating the disparity so that the depth information around the gaze position is maximally preserved.

Evaluation of Adaptive Interaction Systems for Virtual Museum Development

Virtual Museum (VM) is an application of Virtual Reality (VR) technology generating realistic visualization and sensation to convince museum visitors to interact with digital content. There are many immersive VR devices that support interactive VM applications. We investigate appropriate devices for interaction within VM. We proposed a Storytelling platform to achieve device organization without modification, the story and interaction were self-adapted to the selected device. Three types of interactive content were designed on our Storytelling platform to be applied on different interaction systems: a 2D standard display, a 3D stereoscopic display and a full immersive CAVE. The results showed different performances of each system supporting VM developers to select an appropriate interaction system. The evaluation contributes to the design of content and interaction of VM development with more efficiency based on user requirements.
 HIGHLIGHTS
 
 Three types of interactive content were designed on our Storytelling platform to be applied on different interaction systems: A 2D standard display, a 3D stereoscopic display, and a full immersive CAVE
 The 2D Powerwall system with a wide range of views provides immersion. However, with two-dimensional displays, users lack depth perception
 Users spent more time in selection and manipulation in the 3D stereoscopic system because depth perception is added
 The CAVE system has user attraction or holding power, users spent more interacting time
 
 GRAPHICAL ABSTRACT

Polarization Selective Transparent Electrode With Patterned Metal for the 3D Display Pixel

We propose a polarization selective transparent electrode (PSTE) utilizing a rectangular-shaped metal nano-wire structure. The performance of the PSTE was evaluated with simulation based on finite element method (COMSOL Multiphysics). Parametric studies have been carried out to give a guide for geometric parameter selection to meet the requirement of the target application. According to the studies, 70 nm by 800 nm rectangular metal grid, having a thickness of 100 nm and linewidth of 30 nm were recommended to keep higher than 61% transmittance, 24 dB extinction ratio, and lower than 5 Ω/sq sheet resistance. As an application of PSTE, a design idea about crosstalk reduction of the passive stereoscopic 3D display is proposed by presenting its pixel structure employing the proposed PSTE. The light extraction efficiency of the proposed pixel employing PSTE structure was also evaluated and compared to the structure employing the lossless ITO (Indium Tin Oxide), by measuring extracted light output power from incoherently distributed dipole sources excited in the emission layer. Degradation of the extraction efficiency below 14 percent point was expected compared to the lossless ITO for all the primary color wavelength range.

Comparing and Combining Virtual Hand and Virtual Ray Pointer Interactions for Data Manipulation in Immersive Analytics.

In this work, we evaluate two standard interaction techniques for Immersive Analytics environments: virtual hands, with actions such as grabbing and stretching, and virtual ray pointers, with actions assigned to controller buttons. We also consider a third option: seamlessly integrating both modes and allowing the user to alternate between them without explicit mode switches. Easy-to-use interaction with data visualizations in Virtual Reality enables analysts to intuitively query or filter the data, in addition to the benefit of multiple perspectives and stereoscopic 3D display. While many VR-based Immersive Analytics systems employ one of the studied interaction modes, the effect of this choice is unknown. Considering that each has different advantages, we compared the three conditions through a controlled user study in the spatio-temporal data domain. We did not find significant differences between hands and ray-casting in task performance, workload, or interactivity patterns. Yet, 60% of the participants preferred the mixed mode and benefited from it by choosing the best alternative for each low-level task. This mode significantly reduced completion times by 23% for the most demanding task, at the cost of a 5% decrease in overall success rates.

The Adoption of a Virtual Reality-Assisted Training System for Mental Rotation: A Partial Least Squares Structural Equation Modeling Approach.

BackgroundVirtual reality (VR) technologies have been developed to assist education and training. Although recent research suggested that the application of VR led to effective learning and training outcomes, investigations concerning the acceptance of these VR systems are needed to better urge learners and trainees to be active adopters.ObjectiveThis study aimed to create a theoretical model to examine how determining factors from relevant theories of technology acceptance can be used to explain the acceptance of a novel VR-assisted mental rotation (MR) training system created by our research team to better understand how to encourage learners to use VR technology to enhance their spatial ability.MethodsStereo and interactive MR tasks based on Shepard and Metzler’s pencil and paper test for MR ability were created. The participants completed a set of MR tasks using 3D glasses and stereoscopic display and a 6-degree-of-freedom joystick controller. Following task completion, psychometric constructs from theories and previous studies (ie, perceived ease of use, perceived enjoyment, attitude, satisfaction, and behavioral intention to use the system) were used to measure relevant factors influencing behavior intentions.ResultsThe statistical technique of partial least squares structural equation modeling was applied to analyze the data. The model explained 47.7% of the novel, VR-assisted MR training system’s adoption intention, which suggests that the model has moderate explanatory power. Direct and indirect effects were also interpreted.ConclusionsThe findings of this study have both theoretical and practical importance not only for MR training but also for other VR-assisted education. The results can extend current theories from the context of information systems to educational and training technology, specifically for the use of VR-assisted systems and devices. The empirical evidence has practical implications for educators, technology developers, and policy makers regarding MR training.

三维立体展示物探AMT剖面资料的一种方法

三维立体展示物探AMT剖面资料的一种方法

Maskless Fabrication of Film-Patterned-Retarder (FPR) Using Wedged Liquid Crystal Cell

Film-patterned-retarder (FPR) is an optical film used in the stereoscopic 3D display and is fabricated using an expensive photomask and nano-wire grid polarizer. This method is expensive and the pitch of FPR is fixed for a given photomask. Here, we introduce a maskless fabrication method for FPR using a wedged liquid crystal (LC) cell. The retardation of the wedged LC cell is continuously increased from one edge to the other. When the polarized monochromatic laser beam (450 nm) passes through the cell, periodically undulated polarization pattern of light is obtained, and can be used to produce FPR by combining with the photo-alignment method. The method does not require the expensive photomask and nano-wire grid polarizer, and the pitch of FPR can be simply controllable by changing the birefringence of LC material with temperature or using a light source of different wavelengths. Thus, this method can provide a simple and cost-effective method for FPR fabrication.

Eye movement measures for predicting eye gaze accuracy and symptoms in 2D and 3D displays

The current study applied Structural Equation Modeling (SEM) to analyze the interrelationship among index of difficulty (ID), environment, saccade duration (SD), revisited fixation duration (RFD), number of fixation (NF), pupil size (PS), eye gaze accuracy (AC), and symptoms simultaneously. SD, RFD, NF, PS, and AC were measured by utilizing the Tobii eye tracker system. Twelve participants were recruited to perform multi-directional tapping task using within-subject design with two different environments (2D screen display and 3D stereoscopic display) and six different levels of ID. SEM showed that ID had significant direct effects on SD and RFD while environment was found had significant direct effects on SD, RFD, PS, AC, and symptoms. Among selected eye movement measures, NF was found to be the best predictor of AC and PS was found to be the best predictor of symptoms. In addition, RFD was also found to be a good predictor of symptoms. Our results found that higher AC was achieved by projecting the image in the 2D screen display with higher ID and it resulted in higher SD and higher NF. Regarding the symptoms, our results found that lower symptoms were achieved by projecting the image in the 2D screen display with lower ID and it resulted in lower PS, and lower RFD.Practitioner Summary: The SEM could provide valuable theoretical foundations to identify the interrelationship among eye movement measures, AC, and symptoms particularly for VR researchers and interface developers.

Glasses-free 3-D visualization with multi-layered transparent cholesteric films.

Fabrication of a three-dimensional (3D) device with volume-filling autostereoscopic imagery provides a unique solution to the accommodation-convergence mismatch problem in a conventional stereoscopic 3D display. We demonstrate a volumetric 3D display consisting of a stack of sequentially-driven transparent cholesteric films that illuminate every point in the display volume to generate a synthetic 3D image. Transparent cholesteric films comprise of the reverse-mode polymer-stabilized cholesteric texture (R-PSCT) that exhibits > 85% transmittance in its off-state (Grandjean texture) and <15% transmittance in its on-state (focal-conic texture). The polymer network in the R-PSCT is formed with the mixture of reactive monomers: RM6 and RM257. The electro-optical measurements show a strongly influence of concentration of each reactive monomer in the total mixture on the optical contrast and driving voltage of R-PSCT films. Hence, we optimize the composition of reactive monomers in R-PSCT to achieve a low driving voltage, high optical contrast and high electro-mechanical stability. Furthermore, we fabricate a multi-surface and a see-through volumetric 3D display prototype that consists an optical element with 15 R-PSCT films that are sequentially-switched with a microcontroller and operated at 250 Hz. A high-speed DLP projector is used to project a time-multiplexed series of two-dimensional images that are used to build the multi-planar volumetric images.

P‐201: Late‐News Poster: Super Multi‐View 3D Display Based on Polarization Multiplexing

In order to overcome the inherent accommodation‐convergence (AC) conflict in stereoscopic 3D display, we proposed a super multi‐view 3D display based on polarization multiplexing for AR/VR applications. Employing 2 LCD devices with orthogonal polarization directions and a pair of polarizing glasses, 2 viewing points can be observed by a human eye simultaneously. We also analyze the factors affecting the depth range in such a display.

Effects of display technologies on operation performances and visual fatigue

The use of 3D stereoscopic display technology in all aspects of life has attracted considerable research attention. However, only few studies have simultaneously considered the effects of stereoscopic display technologies on visual fatigue and operating performances. This study with 36 participants (50% females; mean age = 23.17 years, SD = 3.3) analyzed the effects of display technologies, task complexity, and use time on operation performances, subjective and objective visual fatigue. Results indicated that display technology did not significantly affect the operation performances, whereas task complexity did. However, no interaction took place between them. Display technology had no significant effects on subjective visual fatigue and near-point accommodation (NPA) but affected critical fusion frequency (CFF) significantly. Use time had significant effects on both subjective and objective visual fatigue.

Tiled Stereoscopic 3D Display Wall - Concept, Applications and Evaluation

The Tiled Stereoscopic 3D Display Wall (TS3DW) is a monitor system consisting of six consumer 3D TVs. Two monitors reside on a mobile display mount. One standard configuration is to use them in a 135-degree angle to each other, having one mobile mount in the center, and one at each side. In this way, the system can be transported to multiple locations across a campus as well as used in different application scenarios. This system was already used for a number of research projects and presentations.

Simultaneous object size and depth adjustment for stereoscopic 3D images

To enhance the visual experience of stereoscopic 3D (S3D) images provided for the users, this paper presents a novel method for simultaneous object size and depth adjustment. The two important properties of our methods are that it allows the users to specify the object and its scaling factor to control object's size and depth simultaneously, and it uses mesh warping to control the keypoints of an object with shape preservation, object preservation and visual comfort constraints. As a result, our method achieves high accuracy, visual experience and controllability for S3D display.

Eye movements and visual discomfort when viewing stereoscopic 3D content

The visual brain fuses the left and right images projected onto the two eyes from a stereoscopic 3D (S3D) display, perceives parallax, and rebuilds a sense of depth. In this process, the eyes adjust vergence and accommodation to adapt to the depths and parallax of the points they gazed at. Conflicts between accommodation and vergence when viewing S3D content potentially lead to visual discomfort. A variety of approaches have been taken towards understanding the perceptual bases of discomfort felt when viewing S3D, including extreme disparities or disparity gradients, negative disparities, dichoptic presentations, and so on. However less effort has been applied towards understanding the role of eye movements as they relate to visual discomfort when viewing S3D. To study eye movements in the context of S3D viewing discomfort, a Shifted-S3D-Image-Database (SSID) is constructed using 11 original nature scene S3D images and their 6 shifted versions. We conducted eye-tracking experiments on humans viewing S3D images in SSID while simultaneously collecting their judgments of experienced visual discomfort. From the collected eye-tracking data, regions of interest (ROIs) were extracted by kernel density estimation using the fixation data, and an empirical formula fitted between the disparities of salient objects marked by the ROIs and the mean opinion scores (MOS). Finally, eye-tracking data was used to analyze the eye movement characteristics related to S3D image quality. Fifteen eye movement features were extracted, and a visual discomfort predication model learned using a support vector regressor (SVR). By analyzing the correlations between features and MOS, we conclude that angular disparity features have a strong correlation with human judgments of discomfort.

Validation of Quantitative 3-Dimensional Transesophageal Echocardiography Mitral Valve Analysis Using Stereoscopic Display

The use of 3-dimensional (3D) transesophageal echocardiography (TEE) in perioperative evaluation of the mitral valve (MV) is increasing progressively, including the use of 3D MV models for quantitative analysis. However, the use of 3D MV models in clinical practice still is limited by the need for specific training and the long time required for analysis. A new stereoscopic visualization tool (EchoPixel True 3D) allows virtual examination of anatomic structures in the clinical setting, but its accuracy and feasibility for intraoperative use is unknown. The aim of this study was to assess the feasibility of 3D holographic display and evaluate 3D quantitative measurements on a volumetric MV image using the EchoPixel system compared with the 3D MV model generated by QLAB Mitral Valve Navigation (MVN) software. This was a retrospective comparative study. The study took place in a tertiary care center. A total of 40 patients, 20 with severe mitral regurgitation who underwent mitral valve repair and 20 controls with normal MV, were enrolled retrospectively. The 3D-TEE datasets of the MV were analyzed using a 3D MV model and stereoscopic display. The agreement of measurements, intraobserver and interobserver variability, and time for analysis were assessed. Fair agreement between the 2 software systems was found for annular circumference and area in pathologic valves, but good agreement was reported for prolapse height and linear annular diameters. A higher agreement for all annular parameters and prolapse height was seen in normal valves. Excellent intraobserver and interobserver reliability was proved for the same parameters; time for analysis between the 2 methods in pathologic valves was substantially equivalent, although longer in pathologic valves when compared with normal MV using both tools. EchoPixel proved to be reliable to display 3D TEE datasets and accurate for direct linear measurement of both MV annular sizes and prolapse height compared to QLAB MVN software; it also carries a low interobserver and intraobserver variability for most measurements.

P‐198: Late‐News Poster: Clinical Utility of Stereoscopic 3D Displays in Heads‐up Surgery

Heads‐up surgery is an operation performed while viewing the surgical field on a 3D display instead of using the eyepiece of the microscope. Clinical trials of ophthalmic surgery revealed that this technique shortened the operation time over time. However, some issues were also identified.

Enhancing the Gaming Experience Using 3D Spatial User Interface Technologies.

Three-dimensional (3D) spatial user interface technologies have the potential to make games more immersive and engaging and thus provide a better user experience. Although technologies such as stereoscopic 3D display, head tracking, and gesture-based control are available for games, it is still unclear how their use affects gameplay and if there are any user performance benefits. The authors have conducted several experiments on these technologies in game environments to understand how they affect gameplay and how we can use them to optimize the gameplay experience.