This is simply 'object recognition'. When a lion approaches us, we realise through prior knowledge that the animal is known to be ferocious, dangerous and sometimes doesn't hesitate to kill. With this information we are able to make instant decisions as to the next course of action. A meal at a dinner table tells us it is edible and we can approach it. This 'spatial localisation' is the establishing of where objects are in the surrounding space and time, and is also an important aspect for survival. Another factor necessary for survival is 'perceptual constancy'. This is when objects, although the eyes perceive them to be in motion, are kept constant in terms of appearance. Object recognition, spatial localisation and perceptual constancy are the three main characteristics of perception.
One theory that aims to explain object recognition and constancy is Marr's theory which concerns itself with visual processing. It is also called the computational approach which involves taking two dimensional images and extracting valuable three-dimensional information from them. This theory requires examining the levels of grey in an image, creating a rough sketch, then a 2.5D sketch and representing the image as a 3D model. ...Show more