By Dr. Cary D. Kornfeld, Computer Systems Institute, Department of Informatik
Spatial perception is an essential survival skill. Humans employ a diversity of methods for deriving spatial relationships from visual information: lighting cues, linear perspective, relative size, aerial perspective, occlusion, height relationships, etc. Building a system for stereoscopic imaging requires a background in a variety of topics, ranging from computer systems and performance evaluation to an understanding of the human vision system. A course on Stereoscopic Imaging has recently been developed at ETH Zürich that integrates topics from a variety of areas under the common thread of spatial imaging, providing a broad based, comprehensive study of human vision (anatomy, neurology, perception, image interpretation and construction), digital imaging (representations, encoding, compression, color spaces, solid state capture devices, display devices, color science, analog television), film craft, and the history of stereoscopy.
Course details (winter semester 2005) »» |
|
| |
The History of Stereoscopic Imaging
Sir Charles Wheatstone invented the Stereoscope in 1833 and then spent the next five years exploring this device and its unique effect before announcing his discovery to the world in his publication, Contributions to the Physiology of Vision - Part the first: On some remarkable, and hitherto unobserved, Phenomena of Binocular Vision (1838). He explained that doubleness of vision, caused by retinal disparity, actually produces the depth sensation that we now call stereopsis. A diagram of his original sterescope is depicted on the right.
It is ironic that Wheatstone is widely credited with the invention of the Wheatstone bridge (which he did not invent) but the invention of the stereoscope is only rarely attributed to him. |
|
 |
|
| |
|
|
 |
At approximately the same time and in complete ignorance of Wheatstone's work, Sir David Brewster invented an entirely different method for creating stereoscopic images. Although Brewster is not formally credited with the fundamental discovery of the stereoscope, he was far more influential in popularizing Stereoscopic Imaging.
Stereoscopic imaging has intrigued and fascinated scientists and philosophers for milleniums: Euclid, Kepler, Helmholtz, Edison, Land and many others. |
|
 |
| |
|
|
|
|
| The stereoscope was invented and developed before the advent of photography. Wheatstone commissioned illustrators to create images he suspected would be perceived through his stereoscope as having depth. Among these is a simple, yet non-obvious image that, thirty some years later, was seminal in the debate between Nativism (Ewald Hering) and Empiricism (Hermann von Helmholtz). |
| |
|
 |
The Stereoscope achieved enormous popularity after Queen Victoria expressed amusement when she saw Brewster's prototype at the London Exhibition in 1851. Its popularity grew in tandem with the advent and distribution of photographs. Oliver Wendell Holmes (son of the famous Jurist) designed the most popular viewer within the United States. The decline in interest for stereoscopic photographs occurred when the technology for printing photographs in newspapers and magazines was developed at the end of the nineteenth century. |
| |
|
|
|
 |
|
| |
|
|
|
 |
|
Stereoscopic films had a brief period of popularity in the early 1950's. 65 Stereoscopic Films were released in 1952-3 (e.g. It Came From Outer Space, The House of Wax, Bwana Devil, Creature of the Black Lagoon). A number of other films were produced in 3D but were released and became popular in 2D (e.g. Kiss me Kate, Dial M for Murder, Hondo, Miss Sadie Thompson).
Stereoscopic technology was embraced by Hollywood as one of many attempts to stem the loss of film attendance as television emerged in popularity. Cinerama, Eastman Color, and Cinemascope were also developed by Hollywood during this time to regain audience share. |
|
| |
|
|
|
Creating Stereoscopic Film
|
|
|
|
 |
|
This course is open to all students at ETH but the majority of those who take the course major in Informatik. The course is intended to augment the sometimes narrow focus of specialized classes to include many areas that are proving to be important and highly relevant to the creation of high performance computer systems.
Students are required to complete 5 major projects enabling them to explore the lecture material with "hands-on" depth. They create simple stereoscopic images and video clips using simple and then increasingly more complex optics, camera and computer control systems. They devise a scientific method for establishing the relationship between camera separation and lens characteristics required to capture an arbitrary spatial volume. They are then required to build, using software and hardware, stereoscopic image capture and display systems. |
|
| |
|
|
|
These are then used to create a half dozen ten minute stereoscopic film. By the time they've completed the course they have mastered an impressive range of skills and have learned, via first hand experience, about the subtleties of creating stereoscopic images.
This has become a highly popular course in the Informatik curriculum but is known to require substantial time and effort. Students spend up to 1,000 minutes to produce each minute of stereoscopic video. The design and creation of new stereoscopic hardware can often require weeks of intense work. Review of research literature and the mastery of the complexities of the human visual system require sustained study and a willingness to explore non-traditional areas of study. |
 |
|
| |
|
|
|
 |
|
The course studies the perception of depth in human vision from a variety of perspectives. It presents a historical survey of Stereoscopic Imaging with a focus on key deveolpments, interesting inventions and seminal products (e.g. Holmes Stereoscope, Gruber's ViewMaster). Students are given an intensive series of lectures on the neurology of vision including a detailed examination of the anatomy of the eye (e.g. the optical properties of the lens and cornea using Snell's law to derive the characteristics of the hybrid lense system) and of the brain centers associated with vision, with a emphasis on tracing the processing of visual information through the brain, in those areas associated with known depth cues (e.g. retinal displarity in V1, motion parallax in MT). They derive the limits Panum's Fusion zone by means of the anatomy, size and characteristics of the cortical hypercolumns in the visual cortex.
Students are also given a comprehensive survey of digital imaging (e.g. sampling theory, coding, color spaces and conversion, image capture devices and the theory of their operation, image compression algorithms and techniques, analog television, video processing, storage and sychronization, cinematic conversion, de-interlacing, etc.). Finally a series of lectures and exercises in "Film Craft": styles of film, story versus plot, the development of a Narrative film, selection and use of lenses and filters, shooting angles and their implicit meaning, the development and integration of audio, lighting keys, development and creation of a storyboard and finally the management of a substantial film project. Students learn to watch films from the perspective of a film maker and learn to analyze them. The students learn important skills and methods that enable them to create short stereoscopic films. |
|
  |
|
| |
|
|
|
Twenty-five students (plus innumerable friends, siblings and girlfriends) are putting the finishing touches on this year's films. Last year, five good to "surprisingly" good films were produced. One went on to win an award at a traditional film competition (a 2D version, no less). Last year's festival drew several hundred people to a standing room only audience. Additional showings were scheduled to accommodate demand.
This is the World Premiere of these films. There is something very, very special about a film maker's first film. They are invariably uniquely special. Many of the best films ever created were "first films" such as Citizen Kane, 400 Blows, Knife in the Water, THX 1138 and Diva. |
|
 |
|
| |
|
|
|
| © 2006 ETH Zürich | Imprint | November 3, 2006 |
|
| |
|
|
|
| |
|
|
|
| |
|
|
|
