A list of several perception principles RELATIVE BRIGHTNESS

A list of several perception principles

RELATIVE BRIGHTNESS A monocular cue for distance to perceive brighter objects as closer and dimmer objects as more distant.

RELATIVE BRIGHTNESS: The brightness of an object depends on the light reflected from itself and its background. The two inner circles (B) are of equal intensity, yet may appear different because of their backgrounds.

RELATIVE BRIGHTNESS: The Hermann grid (A) is also example of the perceived brightness depending on the surrounding area. The gray spots at the intersection of the white strips do not exist, but are a perceptual effect of the surrounding black squares.

RELATIVE BRIGHTNESS AND EFFECT ON PERCIEVED DISTANCE: The two inner squares are of equal intensity, yet appear different because of their backgrounds. The on the left may appear closer because it is brighter and clearer

Relative Size The center circles in the drawings below are the same size but the on the left looks bigger because it is surrounded by small circles and the on the right looks smaller because it is surrounded by large circles.

PERCEPTUAL CONSTANCY the tendency to perceive objects, especially familiar objects, as constant and unchanging despite changes in sensory input

Definition: The tendency for a visual object to be perceived as having the same brightness under widely different conditions of light. In this picture we perceive that the leaves have the same brightness even though different amounts of light are reflected off of different leaves.

MONOCULAR DEPTH CUES

SIZE CONSTANCY As the distance of an object from us increases, it retinal image becomes smaller. We tend to correctly perceive the object as being farther away, rather than changing in size.

SIZE CONSTANCY As the distance of an object from us increases, it retinal image becomes smaller. We tend to correctly perceive the object as being farther away, rather than changing in size. Sometimes our perception can be fooled, as in this figure, where both silhouetted figures appear to be the same size, but because of the changing background, we interpret the figure on the right to be growing taller as it moves to the right.

Example of size constancy. We perceive the pool balls as the same size, but the smaller ones are perceived as further away.

Analogous to brightness constancy and brightness contrast, we also experience size constancy and size contrast. The size of an object is interpreted relative to the objects around it and in the context of the other cues (e. g. , linear perspective) for size and distance. The man in the pictures above is physically the same size in both photos and he appears normal in size on the left but tiny on the right.

Explanation: This refers to size constancy because the foot is closer to the camera and the people are farther away so the foot looks bigger than the people which makes the foot look like it is stepping on the people…

SHAPE CONSTANCY

rp e t n n o io sit i Als led l a o c On the left, the circle looks closer than the square, on the right, the square looks closer than the circle.

Linear perspective is another monocular depth cue. The distance between the rails is constant in the 3 D scene but gets smaller and smaller in the image. This is a cue for distance. The visual system uses this to compare the sizes of objects. The two lines are the same length but the on top appears bigger because it is seen as being further away and the visual system is compensating for the perspective. This compensation for distance in interpreting size is known as "size constancy".

Sh ad ow of ct pa l Im pt ua rce Pe The 3 white squares are identical to one another and they are placed in exactly the same way with respect to the checkerboard grid underneath. Only the shadows differ, giving the impression that the square on the right is floating higher above the checkerboard.