VisualPerception

++++++++++++++++++++++++++++++++++++++++++

• OpticalIllusion

saccade

*

• http://web.mit.edu/bcs/schillerlab/research/B-EyeMovements/B1-2.html
• http://www.cs.uu.nl/~mehdi/perception/

++++++++++++++++++++++++++++++++++++++++++

Structural Information Theory Structural Information Theory (SIT) is a general theory of pattern perception which aims at explaining why human perceivers prefer certain interpretations of patterns rather than arbitrary ones. The explanation is based on the assumption that the human perceptual system is sensitive to certain types of structural regularities of patterns called iteration, symmetry, and alternation. The relevant SIT papers are as follows:

* Leeuwenberg, E. (1971). A perceptual coding language for visual and auditory patterns. American Journal of Psychology, 84, 307-349.

* Van der Helm, P. and Leeuwenberg, E. (1991). Accessibility: A criterion for regularity and hierarchy in visual pattern code. Journal of Mathematical Psychology, 35, 151-213.

* Van der Helm, P. (1994). The dynamics of Prägnanz. Psychological Research, 56, 224-236.

* Dastani, M. (1998). PhD^? Thesis, University of Amsterdam, The Netherlands. * M. Dastani, Elena Marchiori, and Robert Voorn, Finding Perceived Pattern Structures using Genetic Programming. In the proceedings of Genetic and Evolutionary Computation Conference (GECCO-2001).

* Robert Voorn, Computing Perceptual Structures of Visual Patterns Using Genetic Algorithm, Master Thesis, August 2001.

Visual Communication BioMimetics

• http://insectzoo.msstate.edu/Students/basic.communication.html

Several kinds of flies and beetles can make light. Fireflies (also known as "lightning bugs") are actually beetles that can make flashes of light. The two sexes of these beetles use different codes of flashes to find and recognize each other. The adult firefly produces light in an organ at the end of its abdomen. This light is made when the beetle opens certain air tubes (trachea) so that oxygen can mix with a substance known as luciferin.

Each species of firefly has a different kind of flash pattern. Photinus pyralis, for example, makes a single long flash that is J-shaped as the beetle dives downward while flying. Another species may fly in a straight line and give off three slow flashes in a row, like this: "...flaaash....flaaash.... flaaash...". A third species may make single flashes that get brighter at their end, like this:"...flasH...flasH...flasH... flasH..."

Many butterflies, flies, and other insects use colors for visual communication. Males of some flies have bright spots on their wings. They communicate with females during courtship dances by flitting their colorful wings. Some butterflies have patterns of ultraviolet color on their wings, which people can't see without special instruments. These ultraviolet color patterns are essential for visual communication during courtship of the two sexes of the butterfly.

Some insects have bright red or orange colors that are exposed only when they are threatened by a predator. For example, if a lubber grasshopper is disturbed, it will flash its bright red hindwings. The sudden display of bright red may scare the predator and give the grasshopper time to escape. This is an example of a visual communication that is passed to another species.

---

-- RachelWingfield - 16 Mar 2004

to top