Head tracking two-image 3D television displays

The research covered in this thesis encompasses the design of novel 3D displays, a consideration of 3D television requirements and a survey of autostereoscopic methods is also presented. The principle of operation of simple 3D display prototypes is described, and design of the components of optical systems is considered. A description of an appropriate non-contact infrared head tracking method suitable for use with 3D television displays is also included. The thesis describes how the operating principle of the displays is based upon a twoimage system comprising a pair of images presented to the appropriate viewers' eyes. This is achieved by means of novel steering optics positioned behind a direct view liquid crystal display (LCD) that is controlled by a head position tracker. Within the work, two separate prototypes are described, both of which provide 3D to a single viewer who has limited movement. The thesis goes on to describe how these prototypes can be developed into a multiple-viewer display that is suitable for television use. A consideration of 3D television requirements is documented showing that glassesfree viewing (autostereoscopic), freedom of viewer movement and practical designs are important factors for 3D television displays. The displays are novel in design in several important aspects that comply with the requirements for 3D television. Firstly they do not require viewers to wear special glasses, secondly the displays allow viewers to move freely when viewing and finally the design of the displays is practical with a housing size similar to modem television sets and a cost that is not excessive. Surveys of other autostereoscopic methods included within the work suggest that no contemporary 3D display offers all of these important factors

Laser Scanning Based Autostereoscopic 3D Display with Pupil Tracking

Abstract-An autostereoscopic 3D display based on direct-view RGB laser projection via a transparent display screen is presented. Dynamic exit pupils are formed at the target eye locations with the help of a pupil tracker

One-stop measurement model for fast and accurate tensor display characterization

Many light field displays are fundamentally different from other displays in that they do not have quantized pixels, quantized angular outputs, or a physical screen position, which can make definitions and characterization problematic. We have determined that it is more appropriate to express the spatial resolution in terms of spatial cutoff frequency rather than a physical distance as in the case of a display with actual quantized pixels. This concept is then extended to also encompass angular resolution. The technique exploits the fact that when spatial resolution of a sinusoidal grating pattern is halved, its contrast ratio is reduced by a known proportion. An improved model, based on an earlier design concept, has been developed. It not only can be used to measure spatial and angular cutoff frequencies, but also can enable comprehensive characterization of the display. This model provides fast, simple measurement with good accuracy. It does not use special equipment or require time-consuming subjective evaluations. Using the model to characterize images in a rapid, accurate manner validates the effectiveness of this technique.NRF (Natl Research Foundation, S’pore)Accepted versio

Time-multiplexed multi-view three-dimensional display with projector array and steering screen

A novel time-multiplexed multi-view three-dimensional (3D) display has been implemented using a projector array to provide the image source and an angular steering-screen module to generate multiple high density horizontal views. The liquid crystal (LC)-based steering screen was specially developed to deflect light beams over a small range and operate in synchronism with the projector array with the use of a customized FPGA driver. The prototype produces vivid color 3D scenes with smooth parallax to multiple viewers. The experimental results verify the proposed multi-projection time-multiplexed multi-view 3D display method that uses a steering screen to produce dense views. Displaying both static and dynamic 3D contents is achieved in our implemented 36-view 3D display prototype. The results of crosstalk measurements are given and analyzed to evaluate the display performance.NRF (Natl Research Foundation, S’pore)Published versio

3-D television: Developing a multimodal multiviewer TV system of the future

Abstract -Under the European Union funded Advanced Three-dimensional Television System Technologies (ATTEST) project, De Montfort University (DMU) is developing a 3D display system targeted specifically at domestic television applications. This system uses a modified transmissive LCD panel together with novel backlighting and optics to project multiple viewing regions, or exit pupils, into the viewing space. These exit pupils are located in space using a head tracker. The display accommodates multiple viewers simultaneously and imposes no physical constraints, such as special eyewear. Viewers may move freely over a "typical" room-sized area. The design of the backlighting facilitates many other display regimes beyond the "standard" 3DTV mode in which each viewer sees the same image pair. Keywords -3D television, autostereoscopic, multiviewer, liquid-crystal display. Introduction The DMU 3DTV display uses a new approach to generating multi-viewer full-freedom-of-viewer-movement autostereoscopic television. The display consists of two main components. The first is a spatially multiplexed screen that interlaces left-and right-eye images on alternate lines of a LCD panel. The second is an assembly comprising lens arrays, LED illumination sources, and folding mirrors that direct separate left-and right-eye light beams through the LCD screen to the left and right eyes, respectively, of each viewer. By projecting only the left-eye screen image to the left eyes of viewers and the right-eye screen image to the right eyes of viewers, 3D can be seen by multiple mobile viewers without the use of special glasses Spatial image multiplexing In order to perform spatial image multiplexing on the LCD screen, light from two distinct sets of steering optics is directed to the appropriate pixel rows on which the left and right images are displayed on the LCD

Salience guided depth calibration for perceptually optimized compressive light field 3D display

Multi-layer light field displays are a type of computational three-dimensional (3D) display which has recently gained increasing interest for its holographic-like effect and natural compatibility with 2D displays. However, the major shortcoming, depth limitation, still cannot be overcome in the traditional light field modeling and reconstruction based on multi-layer liquid crystal displays (LCDs). Considering this disadvantage, our paper incorporates a salience guided depth optimization over a limited display range to calibrate the displayed depth and present the maximum area of salience region for multi-layer light field display. Different from previously reported cascaded light field displays that use the fixed initialization plane as the depth center of display content, our method automatically calibrates the depth initialization based on the salience results derived from the proposed contrast enhanced salience detection method. Experiments demonstrate that the proposed method provides a promising advantage in visual perception for the compressive light field displays from both software simulation and prototype demonstration.National Research Foundation (NRF)Accepted versionDr. WANG Shizheng is financially supported by the Chinese Academy of Science, HundredTalent Program (2018-2020). This work was supported by National Research Foundation Singapore (NRF-CRP11- 2012-01)

Latest research at the advanced displays laboratory at NTU

There are many basic ways of providing a glasses-free 3D display and the three methods considered most likely to succeed commercially were chosen for our current research, these are; multi-layer light field, head tracked and super multiview displays. Our multi-layer light field display enables a far smaller form factor than other types, and faster algorithms along with horizontal parallax-only will considerably speed-up computation time. A spin-off of this technology is a near-eye display that provides focus cues for maximizing user comfort. Head tracked displays use liquid crystal display panels illuminated with a directional backlight to produce multiple sets of exit pupil pairs that follow the user's eyes under the control of a head position tracker. Our super multiview display (SMV) system uses high frame-rate projectors for spatio-temporal multiplexing that give dense viewing zones with no accommodation/convergence (A/C) conflict. Bandwidth reduction is achieved by discarding redundant information at capture. The status of the latest prototypes and their performance is described; and we conclude by indicating the future directions of our research.NRF (Natl Research Foundation, S’pore

Head tracked single and multi-user autostereoscopic displays

This paper describes the authors' development of single user and multi-user 3D displays that do not require the wearing of special eyewear (autostereoscopic) and employ head position tracking in order to enable a large degree of freedom of viewer movement. This makes them particularly suited to TV applications. The results of human factors work on the displays will also be described. Finally, current development based on prior work is explained