Visual perception

Syed Ali RazaLecturerDepartment Of Computer ScienceGC University Lahore

Sensation

Sensations can be defined as the passive process of bringing information from the outside world into the body and to the brain. The process is passive in the sense that we do not have to be consciously engaging in a "sensing" process.

PerceptionPerception can be defined as the active process of selecting, organizing, and interpreting the information brought to the brain by the senses.

Basics of perception

Illusion

Seeing things that ARE NOT THERE and ARE THERE

Approaches of perception

Bottom-Up (Stimulus- Driven) PerceptionPhysical characteristics of stimulus drive perception.

Top-Down (Goal-Driven) PerceptionKnowledge, expectations, or thoughts influence perception.

Interactive PerceptionPerception is driven by both at the same time.

Bottom-up perception

Direct Perception Template Theories Feature- Matching Theories Recognition by Component Theories

Direct perception

Template theory

Feature matching

Recognition by component

Top-down perception

Object perception

Viewer- CenteredIndividual stores the way the object looks to him or her.The shape of the object changes, depending on the angle from which ones look at it. A number of views of the object are stored, and when ones try to recognize an object, ones have to rotate that object in his/her mind until it fits one of the stored images.Object- CenteredIndividual stores a representation of the object, independent of its appearance to the viewer.

Gestalt law

Patterns and forms perception

Feature Analysis Configurationally Analysis

Depth perception