Visual Perception Principles

1. Visual Perception Principles By Jessie Parker

2. Visual perception • Visual perception is the ability to interpret the surrounding environment by processing information that is contained in visible light. Also known as eyesight, sight, or vision

3. Gestalt visual perception principles • Figure-ground organisation • Closure • Similarity • Proximity

4. Figure-ground organisation • Figure-ground organisation is used when you read this sentence, the words printed in black (figure) stand out against the white paper (ground). When we use figure-ground we organize visual information by perceptually dividing a visual scene into a ‘figure’.

5. closure • Closure refers to the perceptual tendency to mentally ‘close up’, fill in or ignore gaps in a visual image and to perceive objects as complete ‘whole’.

6. similarity • The principle of similarity involves the tendency to perceive parts of a visual image that have similar features – such as size, shape, texture or colour.

7. proximity • The principle of proximity (or nearness) is the tendency to perceive parts of a visual image which are positioned close together as belonging together in a group.

8. Depth principles • Binocular depth cues • -Convergence • -Retinal disparity • Monocular depth cues • -Accommodation • -Pictorial cues (there are five of these) 1) Linear perspective, 2) Interposition, 3) Texture gradient, 4) Relative size, 5) Height in the visual field.

9. Binocular depth cues • Binocular depth cues require the use of both eyes working together in order to provide information to the brain about depth and distance.

10. convergence • Convergence involves the brain detecting and interpreting depth or distance from changes in tension in the eye muscle that occur when the two eyes turn inwards to focus on objects that are close.

11. Retinal disparity • Retinal disparity refers to the very slight difference (disparity) in the location of the visual images on the retinae.

12. Monocular Depth cues • Monocular depth cues require the use of only one eye to provide information to the brain about depth and distance, but they also operate with both eyes.

13. Accommodation • Accommodation involves the automatic adjustment of the shape of the lens to focus an object in response to changes in how far away the object is.

14. Pictorial cues • Artists use pictorial cues to create depth and distance on two dimensional surfaces such as paper and canvas. • There are five pictorial cues • 1. Linear perspective • 2. Interposition • 3. Texture gradient • 4. Relative size • 5. Height in the visual field

15. Linear perspective • Linear perspective is the apparent convergence of parallel lines as they recede (‘go back’) in the distance. For example when you are on a long straight road and you look ahead the road will appear to be narrowing.

16. Interposition • Interposition, or overlap as it is also called, occurs when one object partially blocks or covers another, and the partially blocked object is perceived as further away that the object that obscures it.

17. Texture gradient • Texture gradient refers to the gradual reduction of detail that occurs in a surface as it disappears into the distance, compared to a surface that is close and seen in fine detail.

18. Relative size • Relative size is the tendency to visually perceive the object that produces the largest image on the retina as being closer, and the object that produces the smallest image on the retina as being further away.

19. Height in the visual field • Height in the visual field refers to the location of objects in our field of vision, objects that are closer to the horizon are seen as being more distant than object located further away from the horizon.