Autostereoscopic Research Articles

A 2D/3D Switchable Directional-Backlight Autostereoscopic Display Using Polymer Dispersed Liquid Crystal Films

A 2D/3D switchable autostereoscopic display with spatial and sequential hybrid control (SSHC) using polymer dispersed liquid crystal (PDLC) films is studied. The light propagation in the SSHC system is simulated with a Monte Carlo ray-tracing method. Relationship between the 2D uniformity and anisotropy factor as well as mean free path is obtained by a series of simulation cases. The uniformity reaches over 85% in simulation. As well, a two-viewpoint prototype is built to give the experimental result. Measurements show that a highly transparent PDLC film can maintain the high-quality 3D performance while a strongly diffusive one can enhance the uniformity in 2D mode. By increasing the driving duty cycle of the backlight units, the issue of luminance attenuation in 2D mode can be addressed. Our technique offers a practical solution for 2D/3D switch in autostereoscopic displays.

Directional view method for a time-sequential autostereoscopic display with full resolution.

A time-sequential autostereoscopic three-dimensional (3D) display using a set of cylindrical optical elements (COEs) as the backlight steering is proposed. The operation principle of the system and its detailed design are described. In our system, the COEs control the direction of the backlight for the proposed system of the user's right and left views. Additionally, the displayed images can be observed under ambient lighting by implementing the high density light-emitting diode (LED) arrays. Compared to the first-generation array display, the image resolution is greatly improved by the addition of the time multiplexing technique. A prototype system using a set of COEs, LED arrays, two linear Fresnel lenses, and an elliptical diffuser is constructed. Here, the directional backlight beams are synchronized with the right and left images alternately displayed on the liquid crystal display (LCD) screen, and two convergent viewing zones are formed alternately in front of the user's eyes; then 3D images are perceived because of persistence of the vision of human eye. The experimental results show that the proposed method is a potential technology for 3D applications such as 3D television.

360 Degree Crosstalk-Free Viewable 3D Display Based on Multiplexed Light Field: Theory and Experiments

A 360° three-dimensional (3D) display is one of the most attractive displays for full parallax in horizontal direction. In this paper, we proposed two 360° crosstalk-free 3D autostereoscopic display methods based on pyramidal mirrors-based 3D light field multiplexing and diaphragms. Display performances of proposed displays were analyzed. We fabricated two 360° display prototypes based on the n-gonal pyramidal mirrors assemblage and flat 3D displays. Moreover, we evaluated our proposed methods by simulations and experiments. Experimental results as well as simulation results were consistent with theoretical analysis based on the geometric optics. Furthermore, the proposed schemes and theories may provide a guideline for light field multiplexing and wide viewing angle augmented reality.

Analysis of the Dependence of the Viewing Zones on the Display Radius in Autostereoscopic 2 View Displays of Horizontally Concave Surface

In autostereoscopic display, ray trajectories through the optic element such as the parallax barrier or the lenticular lens are affected by the radius of horizontally concave display. Using the intersection of the calculated trajectories of the rays coming from the various positions of the autostereoscopic 2 view display of the curved surface, the viewing zones and area of the incomplete separation of the images for the left and right eyes were investigated. The area of incomplete separation of the images for the left and right eyes related to the triangular areas defined by three chief rays coming from the left edge, center, and the right edge. These triangular areas for the curved surface was smaller than those for the flat surface and showed the tendency of the decrease as the ratio of the radius of the curved and the designed viewing distance approached 1/2.

Improved halftoning method for autostereoscopic display based on float grid-division multiplexing.

Autostereoscopic printing is one of the most common ways for three-dimensional display, because it can present finer results by printing higher dots per inches (DPI). However, there are some problems for current methods. First, errors caused by dislocation between integer grids and non-customized lenticular lens result in severe vision quality. Second, the view-number and gray-level cannot be set arbitrarily. In this paper, an improved halftoning method for autostereoscopic printing based on float grid-division multiplexing (fGDM) is proposed. FGDM effectively addresses above two problems. GPU based program of fGDM is enabled to achieve the result very fast. Films with lenticular lens array are implemented in experiments to verify the effectiveness of proposed method which provides an improved three-dimensional performance, compared with the AM screening and random screening.

Scanning Prism with Polymer-Stabilized Blue Phase Liquid Crystals

A scanning prism with polymer-stabilized blue phase liquid crystals (PS-BPLCs) was demonstrated with an impulsive blinking backlight system of high-resolution three-dimensional (3-D) display. The fast switching PS-BPLC prism, whose response time was less than 1 ms, may solve the resolution degradation problem for the autostereoscopic display. Also, the impulsive blinking backlight system may improve the dynamic crosstalk for 3-D perception. By optimizing the device structure and backlight system, the scanning prism-type autostereoscopic display may achieve low crosstalk, about 14%, for high-resolution 3-D display.

Simulation and Control of Display Uniformity in a Backlight Illuminated Image Array

The relative retinal illumination (RRI) distribution of a display system consisting of arrayed backlight units, focusing lenses, and viewing screen is simulated with Monte Carlo ray tracing method. A random scattering model is applied to describe the optical seam effect in the vicinity of the stitching. RRI distribution on the screen viewed at different locations for an autostereoscopic display system is simulated, giving rise to a quantitative description of display inhomogeneity on the screen. The method to achieve a uniform RRI distribution on the screen is proposed. The numerical simulation is tested with experimental verification, and good agreement is obtained. The simulation, experiment, and measurement can be applied as design guidelines for autostereoscopic display, integrated imaging display, and other novel backlight illuminated optical systems.

FVisiOn: 360-degree viewable glasses-free tabletop 3D display composed of conical screen and modular projector arrays.

A novel glasses-free tabletop 3D display to float virtual objects on a flat tabletop surface is proposed. This method employs circularly arranged projectors and a conical rear-projection screen that serves as an anisotropic diffuser. Its practical implementation installs them beneath a round table and produces horizontal parallax in a circumferential direction without the use of high speed or a moving apparatus. Our prototype can display full-color, 5-cm-tall 3D characters on the table. Multiple viewers can share and enjoy its real-time animation from any angle of 360 degrees with appropriate perspectives as if the animated figures were present.

Super-multiview content with high angular resolution: 3D quality assessment on horizontal-parallax lightfield display

The advent of glasses-free 3D super-multiview (SMV) displays has opened up new avenues for experiencing 3D content. Accordingly, perceptual quality assessment of such content assumes significance. In this context, we present the results of subjective and objective quality assessment of static 3D SMV content, conducted with twenty subjects on a glasses-free horizontal-parallax 3D lightfield display. First, we create a multiview image dataset using three real objects, with high angular resolution. The display system generates 3D views from fixed subsets of consecutive images. Next, we extend the standard guidelines of subjective assessment to our evaluation environment. In the course, we make recommendations on acquiring SMV data as well as conducting subjective evaluation. Subsequently, we observe that the existing 2D full-reference (FR) quality metrics, applied to individual 3D views, are inadequate for 3D quality assessment. To fill the gap, we propose a 3D FR objective quality metric. For every 3D view, the proposed metric combines spatial information from each constituent image and angular information (depth cues) from consecutive images. Finally, we show that the proposed metric correlates significantly with subjective scores, outperforming existing 2D metrics. The efficacy of pooling spatial and angular information highlights the fact that angular information plays a crucial role in 3D perception.

Augmented reality three-dimensional display with light field fusion.

A video see-through augmented reality three-dimensional display method is presented. The system that is used for dense viewpoint augmented reality presentation fuses the light fields of the real scene and the virtual model naturally. Inherently benefiting from the rich information of the light field, depth sense and occlusion can be handled under no priori depth information of the real scene. A series of processes are proposed to optimize the augmented reality performance. Experimental results show that the reconstructed fused 3D light field on the autostereoscopic display is well presented. The virtual model is naturally integrated into the real scene with a consistence between binocular parallax and monocular depth cues.

3D Quantitative Evaluation System for Autostereoscopic Display

Quality of three-dimensional (3D) displays depends on optical apparatus setups and image generation algorithms. We present a 3D quantitative evaluation method and develop a corresponding system to evaluate the performance of 3D autostereoscopic display. The evaluation system consists of a set of dedicated 3D evaluation reference patterns, a 3D image acquisition platform and a personal computer for auto-control, image processing, and quantitative analysis. Using the proposed method and system, we evaluate resolution, viewing angle, accuracy of image depth, and quality of displayed image of the 3D autostereoscopic display. Furthermore, we perform the evaluation experiments using two integral photography-based 3D displays. The quantificational evaluation results of main parameters are largely consistent with results of theoretical analysis of evaluated displays and well verify feasibility and availability of the evaluation system. An application experiment using one lenticular-based 3D display is also conducted to verify the universality of our proposed evaluation system.

65-4: Visual Effect Analysis for an Auto-stereoscopic Display Illuminated with Directional Backlight

The visual effect in a directional backlight auto-stereoscopic display is analyzed with Monte Carlo ray-tracing technique. The effect of microstructures on the luminescence uniformity on a liquid crystal screen is simulated and experimentally investigated. Linear Fresnel focusing lens deviating from the ideal case is studied specifically as an image focusing element.

P-69: Studies on 2D/3D Switchable Autostereoscopic Display with Spatial and Sequential Hybrid Control Using PDLC Films

An effective approach to achieve 2D/3D switching in an autostereoscopic display with spatial and sequential hybrid control (SSHC) using polymer dispersed liquid crystal (PDLC) films is proposed. The Monte Carlo method is utilized to analyze the scattering interaction of diffusive PDLC layer within the system. And the experimental result is given for a two-viewpoint SSHC system. The results show that PDLC working as 2D/3D switch is fairly feasible in a directional backlight autostereoscopic display.

80-3: A Fast 2D-3D Switchable Display Using a Polymeric Lenticular Lens Array and an Electrically Suppressed Ferroelectric Liquid Crystal

In this article, we demonstrate a compact fast 2D-3D switchable display device which is achieved by a polarization sensitive micro-lens array and an electrically suppressed helix ferroelectric liquid crystal (ESHFLC) cell. The ESHFLC, functioned as a polarization selector, has a high contrast ratio over 3K: 1 of two perpendicular polarization states, under a low applied electric field 1.7 V/µm. In order to get a DC balancing of the ESHFLC, we design two particular driving scheme for 2D and 3D. Due to the fast response of FLC, we are able to switch between the two display modes in microseconds. Thus such an integrated 2D to auto-stereoscopic 3D switchable display with advantages like low power consumption, ultrafast response and good 3D performance can be widely explored and utilized in TV, cell phones and etc.

80-5: Fast Calculation of Stereoscopic Viewpoints via Fourier Slice Transformation and Boundary In-Painting

We propose a new method of calculating the multiple viewpoints for auto-stereoscopic display based on Fourier slice theorem and boundary in-painting. A set of virtual images are calculated from a 2-D image and a depth mapping in the frequency domain. The proposed algorithm is faster and more accurate than conventional method.

무안경 입체영상의 화질변화에 따른 뇌파 기반 사용자 반응 분석

There have been many studies on subject tests for 3D contents using 3D glasses, but there is a limited research for 3D contents using autostereoscopic display. In this study, we investigated to assess usability of electroencephalogram (EEG) as an objective evaluation for 3D contents with different quality using autosteroscopic display, especially for lenticular lens type. The image with optimal quality and the image with distorted quality were separately generated for autostereosopic display with lenticular lens type and displayed sequentially through lenticular lens for 26 subjects. EEG signals of 8 channels from 26 subjects exposed to those images were detected and correlation between EEG signal and the quality of 3D images were statistically evaluated to check differences between optimal and distorted 3D contents. What we found was that there was no statistical significance for a wave vibration, however b wave vibration shows statistically significant between optimal and distorted 3D contents. b wave vibration observed for the distorted 3D image was stronger than that for the optimal 3D image. This results suggest that subjects viewing the distorted 3D contents through lenticular lens experience more discomfort or fatigue than those for the optimum 3D contents, which resulting in the greater b wave activity for those watching the distorted 3D contents. In conclusion, these results confirm that electroencephalogram (EEG) analysis can be used as a tool for objective evaluation of 3D contents using autosteroscopic display with lenticular lens type.

Quantitative measurement of global crosstalk for 3D display

AbstractA photo‐detecting system based on photo‐detector with calibrated optical response is developed to characterize the global crosstalk of three‐dimensional (3D) displays over the entire display screen. Local screens areas are investigated, revealing that the crosstalk can be very inhomogeneous over the entire screens for typical stereoscopic display and autostereoscopic display. New quantification parameters for crosstalk, including average crosstalk and crosstalk uniformity, are introduced to give a panorama view of the display system. The crosstalk measurement and characterization method not only show good agreement with the practical visual experience, but also give a global quantitative description of crosstalk.

A Review of Recent Results on 3D Effects

Three dimensions or three-dimensional or are expressions that characterize the space around us, as perceived by our vision, in terms of width, height and depth. The term 3D is also (and improperly) used to refer to the representation in synthetic (digital) images, the relief of stereoscopic images or other images in relief and sometimes even the simple stereophonic effect, which Can only render 2D (it is therefore only the calculation of the projected projections, the shadows, the renderings of materials). In mathematics, this notion corresponds to Euclidean geometry in space. The space is marked by three orthogonal axes, contrary to the plane composed of two dimensions. Since its origins and long before the appearance of colour, cinema has exploited stereoscopy, mainly through the processes of anaglyphs. During the 1950 s, the Hollywood studios exploited the polarized filter system and then, from the 2000 s onwards, with the adoption of digital formats, the rooms also equipped the electronic principle with alternating shutter (active glasses). Despite some anaglyphic experiments since the 1930 and 1950 s, the commercial success of television became a reality from the end of the 1990 s to a real industrial development from the year 2000. Two principles and devices for Stereoscopic effects are commercialized: Of the active type with electronic bezels or of the passive type with polarized filter goggles. More complex and costly to industrialize in particular with regard to large screens, auto stereoscopy (relief effect without bezel) was introduced with Alioscopy since the late 1990 s, on the lenticular principle. Stereoscopic videoprojection intended for the general public requires electronic active glasses or a special screen (metallised or offering some refraction of light) associated with passive glasses with polarized filters. Three-Dimensional (3D) effects close to sharp corners of a hole in a plate with finite thickness are investigated in the present contribution. The results from detailed finite element model are analyzed to investigate the stress intensity of various fracture modes caused by the presence of a finite thickness. The results expressed in terms of stressed are compared with some recent equations. The comparison between numerical and theoretical results shows a sound agreement.

Depth-tunable three-dimensional display with interactive light field control

A software-defined depth-tunable three-dimensional (3D) display with interactive 3D depth control is presented. With the proposed post-processing system, the disparity of the multi-view media can be freely adjusted. Benefiting from a wealth of information inherently contains in dense multi-view images captured with parallel arrangement camera array, the 3D light field is built and the light field structure is controlled to adjust the disparity without additional acquired depth information since the light field structure itself contains depth information. A statistical analysis based on the least square is carried out to extract the depth information inherently exists in the light field structure and the accurate depth information can be used to re-parameterize light fields for the autostereoscopic display, and a smooth motion parallax can be guaranteed. Experimental results show that the system is convenient and effective to adjust the 3D scene performance in the 3D display.

Ground autostereoscopic display with new type non-uniform barrier

This paper analyzes the drawbacks of traditional parallax barrier with the uniform slits for large-scale ground autostereoscopic display firstly. And then an approach of designing non-uniform barrier for ground display is proposed by use of the reverse ray-tracing technique and Iterative approximate algorithm. Form the numerical simulation, it is proved that low cross-talk feature of the non-uniform barrier is an advantage relative to traditional parallax barrier.