Live-action stereoscopic feature films are, for the most part, produced using a costly post-production process to convert planar cinematography into stereo-pair images and are only occasionally shot stereoscopically using bulky dual-cameras that are adaptations of the Ramsdell rig. The stereoscopic lens design described here might very well encourage more live-action image capture because it uses standard digital cinema cameras and workflow to save time and money.
The art of stereoscopic cinematography has been held back because of the lack of a convenient way to reduce the stereo camera lenses' interaxial to less than the distance between the eyes. This article describes a unified stereoscopic camera and lens design that allows for varying the interaxial separation to small values using a unique electro-optical polarizing aperture design for imaging left and right perspective views onto a large single digital sensor, the size of the standard 35 mm frame, with the means to select left and right image information. Even with the added stereoscopic capability, the appearance of existing camera bodies will be unaltered.
A brief history of recent developments in electronic stereoscopic displays is given concentrating on products that have succeeded in the market place and hence have had a significant influence on future implementations. The concentration is on plano-stereoscopic (two-view) technology because it is now the dominant display modality in the marketplace. Stereoscopic displays were created for the motion picture industry a century ago, and this technology influenced the development of products for science and industry, which in turn influenced product development for entertainment.
The art of stereoscopic cinematography has been held back because of the lack of a convenient way to reduce the stereo
camera lenses' interaxial to less than the distance between the eyes. This article describes a unified stereoscopic camera
and lens design that allows for varying the interaxial separation to small values using a unique electro-optical polarizing
aperture design for imaging left and right perspective views onto a large single digital sensor (the size of the standard
35mm frame) with the means to select left and right image information. Even with the added stereoscopic capability the
appearance of existing camera bodies will be unaltered.
A stereoscopic 35mm motion picture projection system is described consisting of a sideframe format with high effective
frame area utilization and high brightness optics. The system has been designed to work within the existing motion
picture content creation and distribution infrastructures.
Over 1000 theaters in more than a dozen countries have been outfitted with digital projectors using the Texas Instruments DLP engine equipped to show field-sequential 3-D movies using the polarized method of image selection. Shuttering eyewear and advanced anaglyph products are also being deployed for image selection. Many studios are in production with stereoscopic films, and some have committed to producing their entire output of animated features in 3-D. This is a time of technology change for the motion picture industry.
An improved technique for displaying stereoscopic moving images is described that makes for a more comfortable and
enjoyable viewing experience by reducing the conflict of cues that occurs at the vertical edges of the screen surround
when objects with negative parallax values are partially occluded. One such means for mitigating the vertical surround
edge conflicts is given, in which the convergence of the camera fields is effectively altered to produce the zero parallax
condition in the regions of the image immediately adjacent to the vertical edges of the screen surround. The transition is
proportional to the proximity to the vertical edge and controlled proportionately. The net effect of this edge treatment is
to allow for an increase in the projected image's parallax budget, thereby heightening the overall depth effect.
Advances in stereoscopic display technologies, graphic card devices, and digital imaging algorithms have opened up new possibilities in synthesizing stereoscopic images. The power of today’s DirectX/OpenGL optimized graphics cards together with adapting new and creative imaging tools found in software products such as Adobe Photoshop, provide a powerful environment for converting planar drawings and photographs into stereoscopic images. The basis for such a creative process is the focus of this paper. This article presents a novel technique, which uses advanced imaging features and custom Windows-based software that utilizes the Direct X 9 API to provide the user with an interactive stereo image synthesizer. By creating an accurate and interactive world scene with moveable and flexible depth map altered textured surfaces, perspective stereoscopic cameras with both visible frustums and zero parallax planes, a user can precisely model a virtual three-dimensional representation of a real-world scene. Current versions of Adobe Photoshop provide a creative user with a rich assortment of tools needed to highlight elements of a 2D image, simulate hidden areas, and creatively shape them for a 3D scene representation. The technique described has been implemented as a Photoshop plug-in and thus allows for a seamless transition of these 2D image elements into 3D surfaces, which are subsequently rendered to create stereoscopic views.
A stereoscopic display based on the viewing of two eye-multiplexed co-planar images correlated by perspective disparity exhibits a three-dimensional lattice of finite-sized volume elements -- virtual voxels -- and corresponding depth planes whose number, global and individual shapes, and spatial arrangement all depend on the number, shape, and arrangement of the pixels in the underlying planar display and on the viewer's interocular distance and viewing geometry relative to the display. This paper illustrates the origin and derives the quantitative geometry of the virtual voxel lattice, and relates these to the quality of the display likely to be perceived and reported by a typical viewer.
The Parallax Player is a software application that is, in essence, a stereoscopic format converter. Various formats may be inputted and outputted. In addition to being able to take any one of a wide variety of different formats and play them back on many different kinds of PCs and display screens. The Parallax Player has built into it the capability to produce ersatz stereo from a planar still or movie image. The player handles two basic forms of digital content - still images, and movies. It is assumed that all data is digital, either created by means of a photographic film process and later digitized, or directly captured or authored in a digital form. In its current implementation, running on a number of Windows Operating Systems, The Parallax Player reads in a broad selection of contemporary file formats.
StereoGraphics Corporation has introduced a new flat-panel autostereoscopic display, the SynthaGram. It produces bright, clear and satisfying three-dimensional images that may be viewed from a substantial angle of view by many observers. A progression of perspective views, like that used by the parallax panoramagram, is created either by computer or photographic means. Each view is sampled at the sub-pixel level and mapped by means of a process called Interzigging. The resultant Interzigged image is a sub-pixel map of spatial information. The map is displayed on a flat panel screen - in the present case a liquid crystal display. A lenticular screen overlays the flat-panel display, but the direction of the lenticule boundaries are angled to the vertical. The technology, we believe, is the basis for electronic autostereoscopic display solutions for many applications.
We have used the eclipse method for a pair of liquid crystal (LC) projectors so they produce a stereoscopic image, with very little cross-talk, by taking advantage of the fact that liquid crystal projectors have long image lag. We operate an eclipse system whose rate is independent of the field rate of the projectors since the liquid crystal image is sustained more or less continuously. In this way we are turning a problem associated with these projectors into the method for projecting good stereoscopic images. We use a pair of LC shutters at the projector lenses opening and closing out of phase with each other, eclipsing the images at a high enough rate to preclude flicker. The selection device eyewear uses left and right LC shutters that run in synchrony with the projector shutters. A stereoscopic images is viewed the right image is seen by the right eye when the right shutters for both projector and eyewear are open. The left eye image is blocked by both eyewear and projector shutters, and so on, vice versa, field after field. The fields have been, in effect, created by the projector shutters and are unrelated to the actual video field rate. An important aspect of this approach is that the resultant stereo image has very low cross-talk because the process is dependent upon the dynamic range of the LC shutters and eliminates any contribution of cross-talk from pixel hysteresis.
StereoGraphics Corporation introduced the push-pull ZScreen using (pi) -cell technology for direct viewing of stereoscopic images on monitors in 1987. A version of the push-pull product continues to be manufactured for use in conjunction with high-end CRT based projectors. In 1998, we reintroduced a (pi) -cell modulator, of a different design, which is intended for use with a CRT based monitor image.
StereoGraphics Corporation has over a decade of experience providing stereoscopic display products for use with UNIX workstations and has become the leading vendor in that marketplace. To achieve this kind of marketplace acceptance, the company had to go to great lengths to solve a myriad of interface issues that arose because of a lack of standardization. More recently, the company developed and marketed a PC product that operates under DOS and Win95. This product specifically solves the problem of using shuttering eyewear for a flickerfree result when used in conjunction with non-stereo-ready video boards, i.e., those that do not operate at a high field rate. With the growing acceptance of WinNT workstations in applications such as mechanical CAD, a design effort was undertaken to create a new family of products that would prove ease of interface with this new workstation infrastructure. This paper describes the development of StereoGraphics products designed specifically for the WinNT workstation. The interface task is greatly simplified for machines employing video boards which include quad buffering, operate at a high field rate and use the VESA Standard Connector for Stereoscopic Display Hardware. The new products include: An infra-red emitter compatible with CrystalEyes, low cost wired shuttering eyewear of high optical quality,an d an emitter that will work with non-stereo-ready video boards. In addition, the company's polarization modulator, the ZScreen, which uses passive eyewear, also interfaces with the new NT infrastructure.
Byatt describes the use of a multiple electrode or segmented liquid crystal switchable polarizer in combination with a monitor for a field sequential stereoscopic display. The benefit of this approach is to suppress crosstalk caused by the phosphor afterglow. The multiple-segment Byatt modulator has a noticeable drawback: the segments are visible as individual units. In our paper we describe how to make these segments invisible.
There are several formats for time-shared stereoplexed electronic displays. A stereo-vision format is the technique used for assigning pixels (or lines, or fields) for the left and right images, enabling them to be available at the display screen as an image with true binocular stereopsis. These days most graphics workstations intrinsically output a high field rate, and don't require the above-and-below solution once used for workstations and now more commonly used on PCs. Another approach uses spatial multiplexing of rows or columns, either for individual selection devices or autostereoscopic displays. A new format, the white-line-code (WLC) system, was developed for PCs and offers a low cost but high resolution. This format doesn't care if the left and right fields are in interlace or progressive scan modes, and it doesn't care about field rate.
SimulEYES VRTM, a new product for mass consumer electro-stereoscopic displays, is described. The system uses a unique indexing approach to allow content providers latitude in choosing the display mode. Board and PC manufacturers may also take advantage of the elegance of the solution by building in the SimulEYES VR capability. Hardware components consist, in part, of two custom chips which may be integrated at the board level, or employed in a VGA port dongle and control box. The liquid crystal shuttering eyewear is of a unique ergonomic design which is comfortable for people of all ages and most facial types, even when wearing eyeglasses.
This paper is about a field-sequential electro-stereoscopic virtual reality (VR) viewing device which incorporates electro-optical shutters, and lenses that aid accommodation and convergence. Each eye looks through a combination of prismatic and positive-diopter lenses, and the same shutters used in CrystalEyesR eyewear are used for image selection. This is the first lenticular stereoscope to employ the time-multiplexing technique with superimposed images and shutters functioning as a kind of electronic septum. The result is a product with relatively low cost, high resolution, and a wide field of view.
New products are described for real-time viewing of flicker-free stereoscopic video and the multiplexing/demultiplexing of two channels of picture information within a standard video channel. The technique used in the new products is superior to prior commercially available stereoplexing approaches, eliminating the need for a line-doubling scan converter, and increasing vertical resolution while decreasing the stairstepping of diagonal lines.
Recently there has been significant activity in the attempt to develop autostereoscopic electronic displays. An interesting variation of the panoramagram, the moving slit technique, was described by Collender in the early seventies, and there have been various new types of volumetric display techniques, such as the Spacegraph acoustical mirror and the Texas Instruments laser scanned revolving surface. Lately liquid crystal technology has been employed by NTT and Dimension Technologies, offering the promise of a true three- dimensional display without the need for individual viewing devices. There are fundamental considerations with regard to presentation of visual information that provide constraints with regard to making such products competitive compared with current field-sequential electronic displays. These field-sequential displays have been successful in the marketplace and provide a standard against which the performance of new products must be measured. Products like CrystalEyesR allow any number of spectators to view the image, and have a high degree of compatibility with the present computer graphics and video infrastructures -- an important issue for manufacturers integrating such products into, for example, workstations, and for the user in terms of price and ease of use.
The historical development of shutters employed in selection devices used for field-sequential electro-stereoscopic displays is traced. The discussion encompasses mechanical shuttering systems used for motion pictures and vector computer graphics displays, and early electro- optical shuttering systems using PLZT ceramic material. The art of electro-stereoscopy was advanced with the introduction of the surface mode liquid crystal device, which is ten times faster than the prior and more commonly employed twisted nematic device. The types of surface mode devices are described, including those mounted in front of display screens used in conjunction with passive glasses, and the achromatic shutter used in the latest wireless active shuttering eyewear.
In the last two or three years electro-stereoscopic display
systems using large liquid crystal panels have become commonplace.
These devices change the polarization characteristics of
the light emitted by the display at video field rate so that
passive eyewear employing polarizers may be used. The size of
such displays is limited because liquid crystal factories aren't
set up to handle panels larger than 19 inches in diagonal. In
addition, the present product is costly to manufacture and larger
panels would be even more costly.
The new battery powered CrystalEyesTM product uses wireless
eyewear with active liquid crystal lenses, having a fiftieth of
the area of the larger panels. The eyewear receives information
from an infrared emitter, allowing the lenses to occlude in
synchronization with the field rate. There is no size limitation
with regard to the display screen, and the clumsy tethering
cable of prior active eyewear has been eliminated. Moreover, the
cost of the new product is considerably lower than that of the
large liquid crystal panels, and the performance is superior.