Chapter 2 Principles of Stereoscopic Depth Perception and ...

2.2. Human depth perception
although many of the applied concepts and evaluations are also relevant
to other application areas.
This chapter first presents an overview of the basic concepts underlying
human stereoscopic depth perception (2.2). Next, a brief review and categorization
of stereoscopic display techniques is presented (2.3) followed
by an account of stereoscopic video production, including stereoscopic
cameras (2.4.1), and camera geometry (2.4.2) for both parallel and converging
camera configurations.
2.2 Human depth perception
2.2.1 Stereoscopic vision
When considering three-dimensional vision, we are faced with an interesting
paradox. How can the essentially two-dimensional mosaic of retinal
receptors curved around the back of an eyeball give rise to the perception
of a three-dimensional world How do we make this inferential leap
from image to environment Researchers in the area of 3-D vision assume
that the third dimension is reconstructed by the brain through associating
visual sources of information, often called cues, with information from
other modalities, most notably touch (Bruce, Green & Georgeson 1996). In
Chapter 5 the link between motor activity and visual perception is considered
in more detail, as it relates directly to the way we construct and
experience space.
Complex, natural scenes contain a wide variety of visual cues to depth.
Our visual system utilises monocularly available information such as accommodation,
occlusion, linear and aerial perspective, relative size, relative
density, and motion parallax to construct a perception of depth. The
effectiveness of monocular cues is illustrated by the fact that we can close
one eye and still have a considerable appreciation of depth. These cues
are already available in monoscopic displays, such as traditional 2-D television.
The binocular cues, stereopsis and vergence, require both eyes to
work in concert. Random-dot stereograms or Julesz patterns (Julesz 1971)
demonstrate that in the absence of consistent monocular information,
stereopsis alone provides the visual system with enough information to
extract a fairly accurate estimate of depth and shape.
Binocular disparity is available because the human eyes are horizontally
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