The
visual perception
of shapes is achieved by the organization of forms and their classification as figures or as background.
At first glance, this shape looks like a hexagon, which is a simple two-dimensional shape. However, if you look more intently, you can perceive a three dimensional cube.
This shape is, from the outset, drawn to emphasize three dimensional aspects of the shape, and it is immediately perceived as a cube.
As we observe shapes, we set into action organizational and selection processes which are part of the perception and comprehension mechanism. Our preference is based, according to Gestalt theories, on the 'principle of the elementary shape', i.e. the preference of a simple shape over a complex one. This preference may be explained by the limited capacity of the perceptual mechanism which necessitates prudence in the energy used to process data.
There are ambiguous situations in which two possible organizational structures, two possible visual hypotheses, exist, and the perceptional effort of comprehending either one or the other is identical.
In this example, both images are two-dimensional and equally easy to establish, but they can never be grasped simultaneously.
In this example, changing the background lighting changes the meaning of the image. In both cases, the perception mechanism must make an organizational decision - what to delegate to the background and what to accept as the figure.
A number of image/background organizational principles have been defined, based on examples such as the above two, as follows:
•
Contours which differentiate between figure and background are perceived as being part of the figure.
•
Figures usually have a defined shape, while the background is perceived as being formless.
•
The figure is perceived as being more significant than the background and is remembered for longer periods of time.
•
The
image
is perceived as being closer to the viewer than the background, even if both are at an identical distance from the eye.
