Ian Sexton

Advanced three-dimensional television system technologies

We describe the goals of the ATTEST project, which started in March 2002 as part of the Information Society Technologies (IST) programme, sponsored by the European Commission. In the 2-year project, several industrial and academic partners cooperate towards a flexible, 2D-compatible and commercially feasible 3D-TV system-for broadcast environments. An entire 3D-video chain will be developed. We discuss the goals for content creation, coding, transmission, display and the central role that human 3D perception research will play in optimizing the entire chain. The goals include the development of a new 3D camera, algorithms to convert existing 2D-video material into 3D, a 2D-compatible coding and transmission scheme for 3D video using MPEG-2/4/7, and two new autostereoscopic displays. With the combination of industrial and academic partners and the technological progress obtained from earlier 3D projects, we expect to achieve the ATTEST goal of developing the first commercially feasible European 3D-TV broadcast system.

Laser-Based Head-Tracked 3D Display Research

The construction and operation of two laser-based glasses-free 3D (autostereoscopic) displays that have been carried out within the European Union-funded projects MUTED and HELIUM3D is described in this paper. Both use a multi-user head tracker to direct regions viewers referred to as exit pupils to viewers eyes. MUTED employs a direct-view LCD whose backlight comprises novel steering optics and in HELIUM3D image information is supplied by a horizontally-scanned fast light valve whose output is controlled by a spatial light modulator (SLM). The principle of operation, construction and results obtained are described.

Multi-viewer autostereoscopic display with dynamically addressable holographic backlight

— The Multi-User 3-D Television Display (MUTED), designed to provide three-dimensional television (3-D TV) by the display of autostereoscopic imagery to multiple viewers, each of whom should enjoy freedom of movement, is described. Such an autostereoscopic display system, which allows multiple viewers simultaneously by the use of head tracking, was previously demonstrated for TV applications in the ATTEST project. However, the requirement for a dynamically addressable, steerable backlight presented several problems for the illumination source. The MUTED system demonstrates significant advances in the realization of a multi-user autostereoscopic display, partly due to the provision of a dynamic backlight employing a novel holographic laser projector. Such a technology provides significant advantages in terms of brightness, efficiency, laser speckle, and the ability to correct for optical aberrations compared to both imaging and scanned-beam projection technologies.

Head tracked 3d displays

It is anticipated that head tracked 3D displays will provide the next generation of display suitable for widespread use. Although there is an extensive range of 3D display types currently available, head tracked displays have the advantage that they present the minimum amount of image information necessary for the perception of 3D. The advantages and disadvantages of the various 3D approaches are considered and a single and a multi-user head tracked display are described. Future work based on the findings of a prototype multi-user display that has been constructed is considered.

A Roadmap for Autostereoscopic Multi-Viewer Domestic TV Displays

This paper presents a brief overview of the current technologies and technical approaches that may lead to viable and user-acceptable domestic autostereoscopic multi-viewer television displays. It illustrates the performance attributes of the various technological approaches and points to the most likely approaches to succeed within the next 10 years. Finally, it shows possible timescales for the enabling technologies for 3D display, and concludes that multi-user autostereoscopic displays may be the first to gain widespread use

MUTED: Multi-user 3-D display.

Abstract— Research described in this paper encompasses the design and building of glasses-free (autostereoscopic) displays that utilize a direct-view liquid-crystal display whose backlight is provided by a projector and novel steering optics. This is controlled by the output of a multi-user head-position tracker. As the displays employ spatial multiplexing on a liquid-crystal-display screen, they are inherently 2-D/3-D switchable with 2-D being achieved by simply displaying the same image in the left and right channels. Two prototypes are described in this paper; one incorporating a holographic projector and the other a conventional LCOS projector. The LCOS projector version addresses the limitations of brightness, cross-talk, banding in the images, and laser stability that occur in the holographic projector version. The future development is considered and a comparison between the prototypes and with other 3-D displays is given.

Latest developments in a multi-user 3D display

De Montfort University, in conjunction with the Heinrich Hertz Institute, is developing a 3D display that is targeted specifically at the television market. It is capable of supplying 3D to several viewers who do not have to wear special glasses, and who are able to move freely over a room-sized area. The display consists of a single liquid crystal display that presents the same stereo pair to every viewer by employing spatial multiplexing. This presents a stereo pair on alternate pixel rows, with the conventional backlight replaced by novel steering optics controlled by the output of a head position tracker. Illumination is achieved using arrays of coaxial optical elements in conjunction with high-density white light emitting diode arrays. The operation of the steering and multiplexing optics in the prototype display are explained. The results obtained from a prototype built under the European Union-funded ATTEST 3D television project are described. The performance of this model was not optimum, but was sufficient to prove that the principle of operation is viable for a 3D television display. A second prototype, incorporating improvements based on experience gained, is currently under construction and this is also described. The prototype is capable of being developed into a display appropriate for a production model that will enable 3D television to come to market within the next ten years. With the current widespread usage of flat panel displays it is likely that customer preference will be for a hang-on-the-wall 3D display, and this challenge will be met by reconfiguring the optics and incorporating novel optical addressing techniques.

Solving the 3D Problem—The History and Development of Viable Domestic

Domestic television and video display is central to one of the largest consumer electronics markets in the world and the prize for developing a technically capable, and commercially viable domestic-suitable 3D video display system is likely to be great. Producing such a domestic 3D video system places great demands on innovation, research and development, but with recent advances in the enabling technologies such displays are now within our grasp. This paper starts by giving a brief history of the many attempts to produce a viable domestic 3D video display, illustrating the pioneers who first initiated research on 3D domestic displays. This paper then outlines and discusses the essential requirements that would be necessary to fulfil viewer expectations of a viable and usable domestic 3D video display. These demands are then placed in the context of the historical attempts to produce viable 3D displays, showing how these attempts have informed current thinking by outlining the problems of each technology approach. The paper then goes on to describe possible contemporary approaches to producing domestic 3D video displays, discussing the current viability of each, and showing that although there are many current solutions, these are often not suitable for domestic use. The paper then shows the development, based on historical work and contemporary thinking and technology, of viable 3D domestic video displays for both single viewer use and multiple viewer use that are hoped will fulfil the demands of domestic use. The paper summarises with the prediction that within the next 10 years we will see domestic 3D video displays readily available and accepted by the market place.

Multi-user 3D display employing coaxial optics

De Montfort University (DMU) has developed an autostereoscopic display that is targeted specifically at television applications. The display is capable of supplying 3D images to multiple viewers who are not required to wear special glasses, and who are able to move freely over a room-sized area. It operates by producing regions (exit pupils) in the viewing field where either a left or a right image is seen. The positions of the exit pupils are steered to the viewers’ eyes by the use of head tracking. The DMU display consists of an LCD whose conventional backlight is replaced by a steerable optical configuration that is capable of producing several pairs of exit pupils. Left and right images are produced on alternate pixel rows of a single UXGA LCD. This spatial image multiplexing is achieved by the use of a lenticular sheet located between the steering optics and the LCD. The steering optics can produce exit pupils over a large area, but without the aberration and coloration effects associated with other methods. This is achieved using arrays of coaxial lenses in conjunction with high-density white LED array sources.

Helium3D: A Laser-Based 3D Display with '3D+' Capability

In this paper we describe our latest research into 3D displays that do not require the wearing of special glasses (autostereoscopic), can provide 3D to several viewers who have a large degree of freedom of movement and direct a different image to every eye in the viewing field so that motion parallax (the ability to ‘look-around’ objects) and other interesting modes of operation are achieved (‘3D+’). The display operates by providing regions in the viewing field, referred to as exit pupils that follow the positions of the viewers’ eyes under the control of a multi-user head tracker. The display incorporates an RGB laser illumination source that illuminates a light engine. Light directions are controlled by a spatial light modulator and a front screen assembly incorporates a novel Gabor superlens. The principle of operation is explained and the construction of three iterations of the display is described.