Gestalt Principles + Depth Cues

Gestalt psychologists – agree with cognitive constructivists that the mind provides meaning to visual information. The mind uses “organizing principles” as the primary source for giving meaning to visual experience.

However, they partly agree with nativists, in that the organizing principles are present at birth – they are not learned.

The "Law of Simplicity" or the "Law of Pragnanz": every stimulus (the entire figure or configuration) is perceived in its simplest form.

The basic principle = the whole is greater than the sum of its parts. In other words, the whole (a picture, a car) carries a different and altogether greater meaning than its individual components (paint, canvas, brush; or tire, paint, metal, respectively).

In viewing the "whole," a cognitive process takes place – the mind makes a leap from comprehending the parts to realizing the whole

Max Wertheimer, Wolfgang Kohler, and Kurt Koffka = founders of Gestalt theory

Major organizing principles:

Figure/Ground – whole figures separated from their backgrounds based on one or more of a number of possible variables, such as contrast, color, size, etc.

Similarity – things which share visual characteristics such as shape, size, color, texture, or value will be seen as belonging together [c.f., Aristotle]

Proximity – objects or shapes that are close to one another appear to form groups. Even if the shapes, sizes, and objects are radically different, they will appear as a group if they are close together. [c.f., Aristotle]

Closure – We see patterns as completed, even when parts of the pattern are missing or obscured.

Good Continuation – we continue shapes & lines beyond their apparent ending points.

Symmetry or Order – we look for, & appreciate, symmetry, order & balance, even when none actually exists. Order has connotations of stability, consistency and structure.

Closure & good continuation

Closure & good continuation

Similarity – dissimilarity [a.k.a. “anomaly”]

Good continuation (the curved line “behind” the figures)

Closure & good continuation

Proximity

Figure

Figure - Ground

Symmetry

More likely to see Despite the pressure of proximity two overlapping diamonds to group the brackets nearest Less likely to see a small square each other together, symmetryflanked above & below by overwhelms our perception oddly shaped polygons and we see them as pairs

of symmetrical brackets.

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Practice/Examples: Depth Cues

Note: height in the picture plane & the horizon line

The horizon line in pictures is a horizontal line across the picture. It is always at eye level. Things closer to the horizon line are farther away from the viewer. Linear perspective lines recede toward the horizon line.

Thus, below the horizon line, nearer objects are lower in the picture; above the line, nearer objects are higher in the picture.

l. Linear perspective -- apparent convergence of parallel lines in the environment. If you stand between two railroad tracks, they appear to meet near the horizon. Since you know they are parallel, their convergence implies great distance.

2. Relative size. If an artist wishes to depict two objects of the same size at different distances, the artist makes the more distant object smaller.

3. Light and shadow. Most objects in the environment are lighted in ways that create clear patterns of light and shadow. Copying such patterns of light and shadow can give a two dimensional design a three-dimensional appearance.

4. Overlap. (Also known as interposition ) -- an object nearer to the viewer partially blocks another object that is farther away.

5. Texture gradients. Texture of nearer objects will look larger & coarser than of objects farther away.

6. Aerial haze. Smog, fog, dust, and haze add to the apparent distance of an object. Because of aerial perspective, objects seen at great distance tend to be hazy, washed-out in color [“relative brightness”/ vividness], and lacking in detail.

7. Height in the picture plane. Objects that are closer to the horizon line are farther away from the viewer. Thus generally, objects on the ground that are lower in the picture are closer to the viewer.

Melanie Scott

Texture Gradient : texture on rocks, ripples and leaves clearly defined in the foreground, as distance increases texture is lost

Relative Size : size of objects decreases with increasing distance

Interposition: rocks and trees obscure the rocks and trees behind them

Linear Perspective : parallel lines of the bank and stream converge to meet at the horizon line

Aerial Perspective : objects in the foreground are crisp and clear, with distance the background appears hazy

Location in the Picture Plane : the closest objects are farthest from the from the horizon while objects closest to the horizon line are the most distant

Light and shadow provide 3-d effects to the rocks and trees

Tia Smith

Linear Perspective- the two tile lines look like that they are getting closer together.

Relative size - cars look larger closer up than the ones farther away, the person seems really small.

Overlap (interposition)- cars and buildings overlap one another.

Texture gradient - cobblestones get progressively smaller as the road recedes in depth until the stones are not clearly distinguishable from each other.

Relative size – Nearer cars & cobblestones appear larger, hence “closer”

Shadows – around cars, under buildings’ balconies, etc, enhance 3-d effect

Relative height – cars, buildings, cobblestones that are higher in the picture plane appear farther away

Katherine Mansfield - PSY348 – Source: Me & my camera.

Aerial Haze: Grass in background is hazy, everything else is in focus.

Height in picture plane: Flower lower in the picture, hence closer; adding that to relative size & texture makes the flower seem especially close

Linear Perspective: Blades of grass in background, not perfectly parallel, picture gets an upward lift. Lines on petals show recession.

Relative size: Bee vs. yellow bug – bee is larger. Flower is center of attention/focus, largest object.

Overlap: Flower over grass, bee in front of petals and behind the center of flower, yellow bug in front of flower. Petals overlap one another.

Texture: Center of flower roughest part of flower. Bee’s butt looks pretty unpleasant as well.

Shadow: On petals, makes them pop outwards. Darkness in grass gives it depth. Petals are illuminated by sunlight.

• Linear Perspective is evident in the lines on the floor indicating that Batman some distance away from the camera. Likewise the pattern of the buildings converge toward the horizon line.

• Texture gradient – details of nearer buildings, the window frame, and batman are sharper & clearer than in buildings that are farther away.

• Relative size - Batman appears to be as tall as a skyscraper in the background when in reality he is just closer to the camera.

• Overlap - He overlaps the window pillars & outside buildings, indicating that he is closer to the camera than they are.

• Aerial haze – Buildings in the distance are hazier than the nearer buildings.

• Height in the picture plane – nearer buildings & their reflections are lower in the picture. Buildings nearer the horizon line are farther away.

• Shadows & Reflections - The floor is reflective of the buildings outside + Batman’s shadow provides 3-d information.

www.churchofthegeek.com-Tony Jacobson

Brandon Nelson“Wanderer above the Sea of Fog”

Caspar David Friedrich, 1818

Linear Perspective. Texture gradient.

Relative size.

Overlap.

Aerial haze.

Height in the picture plane.

Shadows &/or Reflections.

Assignment

Provide a power point slide similar to the foregoing in which you analyze a picture in terms of the cues for depth in the picture

Due at the ewhpsy@mnstate.edu address by 6:00 p.m., Monday, Feb 14.

Include all of the following cues:

Linear Perspective. Texture gradient.Relative size.Overlap.Aerial haze.Height in the picture plane.Shadows &/or Reflections.