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We propose an autostereoscopic display with a directional backlight unit using an interleaved lens array and an organic electroluminescent display as an active light source. In the proposed system, the screen luminance per unit of power consumption is enhanced and the uniformity of luminance is improved. [ABSTRACT FROM AUTHOR]

Autostereoscopy is usually perceived at finite viewpoints that result from the separated pixel array of a display system. With directionally illuminated autostereoscopy, the separation of the illumination channel from the image channel provides extra flexibility in optimizing the performance of autostereoscopy. This work demonstrates that by taking advantage of illumination freedom, seamless viewpoints in the sweet viewing region, where the ghosting does not cause significant discomfort, are realized. This realization is based on illuminating the screen with a polyline array of light emitting diodes (LEDs), and continuous viewpoints are generated through independent variation in the radiance of each individual LED column. This new method is implemented in the directionally illuminated display for both single and multiple viewers, proving its effectiveness as a valuable technique for achieving a high-quality and high-resolution autostereoscopic display with seamless viewpoints. [ABSTRACT FROM AUTHOR]

Purpose: In general minimally invasive surgical procedures, surgeons are tied to 2D visualization, leading to the loss of depth perception. This can lead to large mental load for the surgeons and may be responsible for the long learning curve. To restore the sense of depth, this study investigated the use and benefits of an autostereoscopic (3D) display during a simulated laparoscopic task. Methods: A mixed reality simulator was developed for comparing the performance of participants while using 2D and autostereoscopic 3D visualization. An electromagnetic sensor was mounted on a physical instrument, and its pose was mapped to the virtual instrument. The virtual scene was developed using Simulation Open Framework Architecture (SOFA). Finite element modeling was used to calculate interaction forces, which were then mapped to visual soft tissue deformation. Results: Ten non-expert participants completed a virtual laparoscopic task, where the subjects were asked to contact eighteen target areas distributed on the surface of the vagina, both in 2D and 3D. Results showed an improvement with 3D vision in task completion time (–16%), total traveled distance (–25%) and errors made (–14%). There was no difference in the average contact forces between the vagina and the instrument. Only the difference in time and forces were shown to be statistically significant. Conclusion: Overall, autostereoscopic 3D showed superiority over conventional 2D visualization. The traveled trajectory increased in 2D as the instrument was retracted more between the targets to avoid contact. The 2D and 3D deformation upon contact seems not to contribute differently to force perception. However, the participants only had visual feedback, but no haptic feedback. Therefore, it could be interesting to include haptic feedback in a future study. [ABSTRACT FROM AUTHOR]

Evaluating the performance of an autostereoscopy is vital to the development of glasses-free three-dimensional display, hence a well-defined and complete characterization is highly necessary. For this purpose, a global and effective scenario is proposed and applied to a directionally illuminated autostereoscopy. The plenoptic function is adopted to characterize the uniformity perceived in various locations in the viewing zone. The crosstalk between binocular channels in different view positions over the entire screen is analyzed. The monocular effective viewing zone is defined by the uniformity and crosstalk while the binocular effective viewing zone is delineated by interpupillary distance. A complete visual modeling is developed that mimics the human vision process. Both simulation and experiment verify the feasibility of the evaluation method. Guided with the characterization, a freeform backlight system with a non-isometric staggered light emitting diode arrangement is optimally designed to generate a seamlessly continuous and uniform viewing zone at different viewing distances. For a nominal 850 mm viewing distance, high quality autostereoscopic display with a lateral viewing range of 560 mm and a longitudinal range of 559 mm is realized.

Autostereoscopy is usually perceived at finite viewpoints that result from the separated pixel array of a display system. With directionally illuminated autostereoscopy, the separation of the illumination channel from the image channel provides extra flexibility in optimizing the performance of autostereoscopy. This work demonstrates that by taking advantage of illumination freedom, seamless viewpoints in the sweet viewing region, where the ghosting does not cause significant discomfort, are realized. This realization is based on illuminating the screen with a polyline array of light emitting diodes (LEDs), and continuous viewpoints are generated through independent variation in the radiance of each individual LED column. This new method is implemented in the directionally illuminated display for both single and multiple viewers, proving its effectiveness as a valuable technique for achieving a high-quality and high-resolution autostereoscopic display with seamless viewpoints.

This paper proposes a novel autostereoscopic display with a directional backlight unit using a linear Fresnel lens array. In the proposed system, different stereoscopic image pairs can be provided to each of the two viewers simultaneously, and the viewing zone where two viewers can see the specific views for their own eyes without interfering with each other's view is enlarged. [ABSTRACT FROM AUTHOR]

Featured Application: In the industrial manufacturing of transparent semi-transparent materials, such as glass, plastic, resin, crystal or liquid, have wide application use. The cleanliness and purity of these components have very strict requirements, such as smart phone cover plates, liquid crystal display panels and camera lenses. The environments for manufacture process of above-mentioned industrial fields usually have high-standard requirement of cleanliness. Impurities or contaminants, such as fiber and dust, are defects that have to be identified, analyzed and controlled during the process. Although defect detection based on machine vision and neural network has made great progress, performing tracking, measurement or identification of targets of interests in a volume is still very challenging. This demand has already become much more urgent and favored by industrial customers to control the manufacturing quality of the multi-layer structure of glass, plastic or other composite material. Meanwhile, in biomedical industries, transparent or translucid materials or medium are in common use. Various targets of interest in a solution or other medium needs to be tracked, identified and analyzed. In this sense, the proposed Autostereoscopy-Raman Spectrometry-based (ARS) measurement methodology and its developed system in this paper are able to be widely applied to but not limited to the production quality control of multilayer glass structure, the manufacture and assembly of precision optical components, the production process control of liquid crystal panel in a clean room or in a laboratory testing, or analyzing equipment for biomedical applications. Three-dimensional compound measurement within a volume of interest is of great importance in industrial manufacturing and the biomedical field. However, there is no current method that can simultaneously perform spatial localization and 3D measurement in a non-scanning manner as well as the identification of material in a volume. In this paper, an Autostereoscopic-Raman Spectrometry-based (ARS) three-dimensional measurement system is proposed. The target object in a large depth range is initially positioned by the autostereoscopic 3D measurement method, and then the accurate position information is cross-checked and obtained by combining the spectral signal. Meanwhile, the spectral signal at the precise excitation position guided by the autostereoscopic signal also carries the material composition information. In order to verify the proposed ARS method, an associated measurement system was developed, and experimental studies of detecting various fibers of different depths in multi-layer glass structure were conducted. The spatial locations and dimensional information of multiple different targets can be measured in a volume, and their material can also be identified at the same time. The average error between the calculated position processed by the ARS system and the actual spatial position is within sub-micron levels, and the success rate of spectrum acquisition reaches 98%. [ABSTRACT FROM AUTHOR]

This work presents a new optical design and the corresponding novel machining strategy to achieve the one step generation of hierarchical optical structures on a flat surface for autostereoscopic effects. The hierarchical structures combine V-groove arrays as a parallax barrier for stereopsis and integrated diffraction gratings with variable grating spacing for motion parallax. The multi-scale surface structures are machined simultaneously using the tool geometry to form V-grooves while utilizing elliptical tool vibration to generate blazed gratings concurrently. An autostereoscopic image with strong depth perception is fabricated with a pixel density exceeding 1,660 pixels per inch. [ABSTRACT FROM AUTHOR]

Depth image based rendering (DIBR) is a popular technique for rendering virtual 3D views in stereoscopic and autostereoscopic displays. The quality of DIBR-synthesized images may decrease due to various factors, e.g., imprecise depth maps, poor rendering techniques, inaccurate camera parameters. The quality of synthesized images is important as it directly affects the overall user experience. Therefore, the need arises for designing algorithms to estimate the quality of the DIBR-synthesized images. The existing 2D image quality assessment metrics are found to be insufficient for 3D view quality estimation because the 3D views not only contain color information but also make use of disparity to achieve the real depth sensation. In this paper, we present a new algorithm for evaluating the quality of DIBR generated images in the absence of the original references. The human visual system is sensitive to structural information; any deg radation in structure or edges affects the visual quality of the image and is easily noticeable for humans. In the proposed metric, we estimate the quality of the synthesized view by capturing the structural and textural distortion in the warped view. The structural and textural information from the input and the synthesized images is estimated and used to calculate the image quality. The performance of the proposed quality metric is evaluated on the IRCCyN IVC DIBR images dataset. Experimental evaluations show that the proposed metric outperforms the existing 2D and 3D image quality metrics by achieving a high correlation with the subjective ratings. [ABSTRACT FROM AUTHOR]

Multiview autostereoscopic three-dimensional (MA3D) displays have the disadvantage that the single-view resolution decreases as the number of views increases. Furthermore, the resolution of MA3D displays is relatively degraded, even though the resolution of two-dimensional displays has increased recently. Therefore, it is unattractive to consumers, and the single-view resolution enhancement of MA3D displays is required. In this study, we developed a method for supplementing the single-view resolution of MA3D displays using a plate beam splitter that can show two MA3D displays simultaneously. By applying our proposed method, the resolution of a single view can increase, and the visual obstruction by the optical plate, which is a problem for MA3D displays, can be solved. In addition, an MA3D display was optically designed and fabricated using a parallax barrier. Finally, the experimental optical results obtained using the proposed method and the only MA3D display were compared. [ABSTRACT FROM AUTHOR]

An emerging enabling technology for electronic holographic displays is the surface acoustic wave (SAW) acousto‐optical modulator family. The authors describe successful demonstration of a horizontal parallax only (HPO) electroholographic display composed of 10 edge‐emitting SAW modulators with 8 channels each. It features innovations in display architecture, modulator design, packaging, and illumination. [ABSTRACT FROM AUTHOR]

Three-dimensional compound measurement within a volume of interest is of great importance in industrial manufacturing and the biomedical field. However, there is no current method that can simultaneously perform spatial localization and 3D measurement in a non-scanning manner as well as the identification of material in a volume. In this paper, an Autostereoscopic-Raman Spectrometry-based (ARS) three-dimensional measurement system is proposed. The target object in a large depth range is initially positioned by the autostereoscopic 3D measurement method, and then the accurate position information is cross-checked and obtained by combining the spectral signal. Meanwhile, the spectral signal at the precise excitation position guided by the autostereoscopic signal also carries the material composition information. In order to verify the proposed ARS method, an associated measurement system was developed, and experimental studies of detecting various fibers of different depths in multi-layer glass structure were conducted. The spatial locations and dimensional information of multiple different targets can be measured in a volume, and their material can also be identified at the same time. The average error between the calculated position processed by the ARS system and the actual spatial position is within sub-micron levels, and the success rate of spectrum acquisition reaches 98%.

We propose a high‐resolution autostereoscopic display that has a deep viewing zone based on time‐multiplexed directional backlight using a large aperture Fresnel lens. When the distance of a viewer from the display changes, the depth of light source should be changed to avoid stereoscopic crosstalk. By combining a DMD projector with layered PDLC screens, the depth of the light source is electronically changed to follow the viewer's motion, which expands the viewing zone in the depth direction. [ABSTRACT FROM AUTHOR]

The representation of three-dimensional volumetric pixels, voxels, is an important issue for the near-to-eye displays (NEDs) to solve the vergence-accommodation conflict problem. Although the holographic waveguides using holographic optical element (HOE) couplers are promising technologies for NEDs with the ultra-thin structure and high transparency, most of them have presented only a single and fixed depth plane. In this paper, we analyze the imaging characteristics of holographic waveguides, particularly to represent the arbitrary voxels and investigate the voxel duplication problem arising from the non-collimated light from the voxels. In order to prevent the image crosstalk arising from the voxel duplication, we propose an adjustment method for the emission angle profile of voxels by using the integral imaging technique. In the proposed method, the sub-regions of elemental images, which correspond to the duplicated voxels, are masked in order to optimize the emission angle of integrated voxels. In the experimental verification, a see-through integral imaging system, based on the organic light-emitting diode display and a holographic waveguide with the thickness of 5 mm, was constructed. The fabricated HOE in the waveguide showed high diffraction efficiency of 72.8 %, 76.6%, and 72.5 % for 460 nm, 532 nm, and 640 nm lasers, respectively. By applying the masked elemental images, the proposed method resulted in a reduced crosstalk in the observed voxels by 2.35 times. The full-color experimental results of see-through holographic waveguide with integral imaging are provided, whereby the observed 3D images are presented clearly without the ghost images due to the voxel duplication problem.

This paper proposes an autostereoscopic display based on time‐multiplexing parallax barrier with fractional numbers of time‐division. We analyze the effect of fractional time‐division to find the conditions where flickers do not stand out even when the number of time‐division is fractional. [ABSTRACT FROM AUTHOR]

We propose a high resolution 3D head‐up display with time‐division multiplexing parallax barrier and concave mirrors to generate a virtual image. In this system the magnified barrier pitch is larger than that of the interleaved image, which causes displacement of slits. This problem is overcome by shifting the slits inward periodically. [ABSTRACT FROM AUTHOR]

Abstract The traditional multi-scopic metrology system makes use of a micro lens array to capture a raw 3D-image of the target surface in a single snapshot through a CCD camera under normal illumination. However, the resolution of the system depends on the matching precision and efficiency of disparity information during the processing of the 3D raw data. In this paper, the a priori knowledge-assisted multi-scopic metrology is studied and an a priori knowledge-assisted multi-scopic metrology system is established which makes use of patterned illumination custom-designed based on the a priori knowledge of the target freeform surface profile. The a priori knowledge provides abundant versatile known information for a precise and efficient matching process so as to enhance the measuring performance. A customized disparity matching process based on the a priori knowledge is developed accordingly for high-resolution 3D surface reconstruction. An experimental study for measuring freeform surface is conducted to verify the feasibility of the proposed a priori knowledge-assisted multi-scopic metrology system through the comparison between that using normal illumination and a priori knowledge-assisted patterned illumination. [ABSTRACT FROM AUTHOR]

This paper proposes a super‐multiview autostereoscopic display with a full HD resolution. 18 views are realized by time‐division sextuplexing, where the orders of color filters in the two LCD panels are reversed to realize 3 fold views. 9 views are generated around each eye to attain a super‐multiview condition. Focal depth effect is confirmed with a prototype system. [ABSTRACT FROM AUTHOR]

In this paper we propose a time‐division multiplexing parallax barrier display whose barrier slits can be shifted by sub‐subpixel unit, which is enabled by using a slanted barrier with a small inclination angle. With this finer control of slit, the viewing zone is enlarged notably. [ABSTRACT FROM AUTHOR]

A high definition aerial stereoscopic display is realized by combining a convex lens and time-division parallax barrier. The proposed system attains a wide stereoscopic viewing zone and little crosstalk without any moving parts. To show an undistorted aerial image in the proposed system, optical distortion by the lens should be corrected, which is realized by real-time optical simulation and texture mapping. Crosstalk and the effect of distortion correction are evaluated with a prototype system. The frame rate of the system is tested under different conditions using different graphic cards. [ABSTRACT FROM AUTHOR]

Advanced displays and natural user interfaces (NUI) are a very suitable combination for developing systems to provide an enhanced and richer user experience. This combination can be appropriate in several fields and has not been extensively exploited. One of the fields that this combination is especially suitable for is education. Nowadays, children are growing up playing with computer games, using mobile devices, and other technological devices. New learning methods that use these new technologies can help in the learning process. In this paper, two new methods that use advanced displays and NUI for learning about a period of history are presented. One of the methods is an autostereoscopic system that lets children see themselves as a background in the game and renders the elements in 3D without the need for special glasses; the second method is a frontal projection system that projects the image on a table in 2D and works similarly to a touch table. The Microsoft Kinect©is used in both systems for the interaction. A comparative study to check different aspects was carried out. A total of 128 children from 7 to 11 years old participated in the study. From the results, we observed that the different characteristics of the systems did not influence the children's acquired knowledge, engagement, or satisfaction. There were statistically significant differences for depth perception and presence in which the autostereoscopic system was scored higher. However, of the two systems, the children considered the frontal projection to be easier to use. We would like to highlight that the scores for the two systems and for all the questions were very high. These results suggest that games of this kind (advanced displays and NUI) could be appropriate educational games and that autostereoscopy is a technology to exploit in their development. [ABSTRACT FROM PUBLISHER]