On Perspective

Specific Cues for Localizing Objects Visually:

• Familiar size- knowledge of the "real" size of a distant object help to indicate how far away it is.
• Relative size.
• Interposition.
• Shadows.
• Linear perspective.
• Convergence.

James Gibson's varieties of perspective:

1. Perspectives of position.
1. Textual perspective. This is the gradual increase in the density of the texture of the surface as it recedes in the distance.
2. Size perspective. As the objects get further away they decreased in size.
3. Linear perspective. Parallel lines converge at a single vanishing point at the horizon.
2. Perspective of parallax.
1. Binocular perspective.
2. Motion perspective. As one moves forward in space, the closer one approaches a stationary object, the faster it appears to move.
3. Perspective independent of the position or motion of the observer.
1. Aerial perspective. Mountains looking like hills.
2. The perspective of blur. Objects in a visual plan other than the one which the eyes are focused will be seen less distinctly.
3. Relative upward location in the visual field. One looks down on objects that are far away.
4. Shift of texture or linear spacing.
5. Shift in the amount of double imagery. If one looks at a distant point, everything between the viewer and the point will be seen as double.
6. Shift in the rate of motion. Those objects which are closed move much more than distant objects.
7. Completeness or continuity of outline. The outline of the nearest object is unbroken and that of the obscured object is broken in the process of being eclipsed, this fact will cause one object to appear behind the other.
8. Transitions between light and shade.

The orders of perception:

1. Intensity- perception that something is there, or something is there that is different from what had been there. Vibrations, disturbances.
2. Sensation- giving meaning to the vibrations, disturbances.
3. Configuration- putting the sensation and intensity into patterns; grouping or classifying them.
4. Control of transition- perceiving when the configuration changes in time. Perceiving motion.
5. Control of sequence- perceiving a transition that is in a cycle.
6. Control of relationship- perceiving cause and effect between objects.
7. Program control- perceiving and creating mental scripts of behavior; goals, plan, etc.
8. Control of principle- behaving within moral rules; acting responsible.
9. Control of system concepts- perceiving general, abstract concepts such as freedom, democracy, life, loyality. These are concepts that are hard to define
10. Meditation- being at one with the universe; acheiving "flow."

Some basic determinants of perception:

1. Constancy.
1. Size constancy.
2. Brightness constancy.
3. Shape constancy.
2. Depth perception.
1. Monocular cues.
1. Relative size.
2. Relative height.
3. Superposition.
4. Atmosphere perspective.
5. Linear perspective.
6. Gradient texture.
2. Binocular cues.
1. Convergence.
2. Disparity.
3. Audiotory localization.
4. Visual clarity.
1. Lateral inhibition.
2. Information processing in the nervous system.