Figure and ground, perception, contour, and grouping are the key concepts involved in the organization of perception. "Depth perception" or "distance perception" refers to the process of observing the environment in three dimensions. We rely on two key types of information termed cues for detecting depth. Cues include visual features such as shape, size, orientation, and color as well as physical differences such as elevation, texture, and temperature.
Visual perception is the process by which we understand our surroundings through the eyes. Visual perception involves both sight and sound. We see what others see and they see what we hear. Another way to think about this is that we see with our brain and listen with our brain. Perception is the receiving system that processes sensory input into meaningful information. Perception depends on the type of sensory receptor cells found in the eye and the amount of stimulation they receive. There are several different types of sensory receptors including touch receptors, taste receptors, smell receptors, and pressure receptors. When these receptors are activated they send signals to the brain which can be interpreted as pain, pleasure, hot, cold, etc.
How does vision work? Light enters the eye and is focused by the lens onto the retina at the back of the eye. The retina is a thin sheet of light-sensitive tissue divided into several areas called retinal fields. Each retinal field contains thousands of neurons that send signals to the brain.
The gestalt theory of visual perception's core concepts include resemblance, continuity, closure, closeness, figure-ground, symmetry, and order (also known as pragnanz). This list does not include all the theories related to visual perception, but rather only those theories that play a major role in explaining how we perceive the world.
Gestalts are useful tools for breaking down complex images into their basic components. These components can then be studied in isolation from one another which allows us to make conclusions about what other parts of the image might look like.
For example, when looking at the picture below, you could assume that the tree is going to have branches, leaves, and be tall. By studying each part of the image separately, you would learn that the eyes and the mind of a person viewing the image find these elements to be important for judging its shape. This means that they must be located somewhere within the image itself or it would be impossible to do so.
These two facts lead to our next principle: Resemblance. The eye and mind are naturally drawn to things that resemble other things that are already known or familiar. This is why shapes that share components with other shapes are easier to see than shapes that are completely new.
Perceptual organization is the process of putting visual aspects together (organization) so that the meaning of the visual as a whole may be determined more easily (perception). The brain has the ability to do this by grouping similar elements together into clusters called "units". For example, when viewing a scene full of objects that are mostly red, it is easier to identify all of the red objects as a whole than it is to identify each individual red object. This ability is called "visual perception" or "visual cognition".
The brain performs this task by using information from our past experience with similar situations. If we have already seen many similar items in a cluster, then the brain knows not to bother processing the individual items too closely. Instead, the brain will group them together into a single unit called a "configuration" or "pattern". For example, if you have ever looked at the face of a clock, you know that the numbers don't just pop out at you when you look at the clock face. Rather, they form a pattern that is familiar to you because you have seen so many clocks with numbers on their faces. The brain uses this knowledge when looking at scenes containing patterns of elements that have been grouped together before. It knows that if something looks like a corner, then it probably is a corner; therefore, it doesn't need to analyze each item individually.