Chapter 2 Principles of Stereoscopic Depth Perception and ...

Recommendations

Info

2. Principles of Stereoscopic Depth Perception and Reproduction requires supplementary information from another cue to be interpreted. An example would be image blur, which provides information about the distance of an object from a fixated object, without indicating which is nearer. Other cues, such as occlusion, familiar size, or linear perspective may act as disambiguators. Generally speaking, the more consistent cues are, the better an accurate depth percept can be established. Cutting & Vishton (1995), based on Nagata (1993), provide a thorough discussion of the relative information potency of depth cues at various distances (see Figure 2.4). Each cue on its own is an ambiguous indicator of distance, layout and surface structure. However, by combining several sources of information this ambiguity may be reduced, even to the point of near-metric accuracy. A detailed treatment of all depth cues is beyond the purpose of this thesis, but interested readers are referred to Cutting & Vishton (1995), Palmer (1999), in particular chapter 5, and Sedgwick (2001). 2.3 Stereoscopic display techniques Stereoscopic display techniques are based on the principle of taking two images and displaying them in such a way that the left view is only seen by the left eye, and the right view only seen by the right eye. There are a number of ways of achieving this (Okoshi 1980, Pastoor & Wöpking 1997, Sexton & Surman 1999). Stereoscopic displays can be categorised based on the technique used to channel the right and left images to the appropriate eyes. A distinguishing feature in this regard is whether the display method requires a viewing aid (e.g., glasses) to separate the right and left eye images. Stereoscopic displays that do not require such a viewing aid are known as autostereoscopic displays. They have the eye-addressing techniques completely integrated in the display itself. Other distinguishing features are whether the display is suitable for more than one viewer (i.e., allows for more than one geometrically correct viewpoint), and whether look-around capabilities are supported, a feature inherent to a number of autostereoscopic displays (e.g., holographic or volumetric displays), but which requires some kind of head-tracking when implemented in most other stereoscopic and autostereoscopic displays. 60
2.3. Stereoscopic display techniques Figure 2.4: Just-discriminable ordinal depth thresholds as a function of the logarithm of distance from the observer, from 0.5 to 10,000 m, for nine sources of information about layout. More potent sources of information are associated with smaller depth-discrimination thresholds, and these thresholds reflect suprathreshold utility. This figure has been adapted from Cutting & Vishton (1995). 61
Page 1 and 2: Chapter 2 Principles of Stereoscopi
Page 3 and 4: 2.2. Human depth perception althoug
Page 5 and 6: 2.2. Human depth perception seen, a
Page 7 and 8: 2.2. Human depth perception provide
Page 9: 2.2. Human depth perception been st
Page 13 and 14: 2.3. Stereoscopic display technique
Page 19 and 20: 2.4. Stereoscopic video production
Page 25 and 26: y l (Y¡ Z) ¢ x r (X¡ Z) ¢ y r (
Page 27 and 28: x l (X¡ Z) ¢ ¤ ¤ sin ( ¡ )(X
Page 31 and 32: Z m ¢ Z i ¢ V £ 2.4. Stereoscopi

Chapter 2 Principles of Stereoscopic Depth Perception and ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?