Binocular disparity is the term given to the difference the fractional difference between an image that exists as a result of the eyes being marginally separated in their place on the face. The image that is received from each eye is just slightly different as a result of this place and must be appropriately processed by the brain into an integrated single image.
The correspondence problem is the problem associated with the process of how the visual perception system goes about finding a way to match pairs of images to arrive at vergence and then go about coding the relative depth of each into a unified image. The difficulty in solving the correspondence problem lies in the fact that a perfect correlation between the pairs of images can only be arrived at under very specific and unusual conditions.
Binocular disparity is related to motion parallax in that each is a method of measuring the perception of depth through the discrepancy that exists as a result of the disparity of image reception onto the retina due to the placement of the eyes. This difference in the position of the eyes is manipulated by the visual system through a process of triangulation that measures distance from the retina to an object and in order to integrate the slight disparity into a unified whole. The differential between the placement of the eyes thus creates a divergence in vantage point that creates the effect of three-dimensionality. Both binocular disparity and binocular parallax are the basis for creating depth when one views an image measuring depth using stereopsis.
2. The picture on the left below shows the so-called caf wall illusion in which
the grout lines (grey lines between the black and white 'tiles') are parallel but
appear to be tilted with respect to each other.
(a) Find and briefly describe in your own words an explanation of the caf wall
illusion that you find convincing (make sure that you do not write more than
One reasonable explanation for how the caf wall illusion works was found on the web site BrainConnection.Com (http://www.brainconnection.com/teasers/main=illusion/cafe-wall). The explanation discovered here suggests that the illusion is the product of the inherent limitations that exist in the way excitatory and inhibitory neurons work together to achieve a balance that facilitates the detection of contrasts. The illusion illustrates how when these neurons attempt to instantaneously detect very fine contrasts, they instead create a distortion by making bright areas appear darker and dark areas appear brighter than they are really are.
(b) Why do you find the explanation you describe