Sampling
By sampling of a continuous function f(x,y) is understood the finding out of the values of samples in regular intervals. We can understand it also as being a transition from a continuous to a discrete case. In this way, we obtain a new function: V(x,y). Concurrently, we will use the fact that 'pixel' is not a point, but an area of the non-zero value. This area is represented by a certain value. We call this 'point sampling' such sampling as where we obtain values at one point. In the case of 'area sampling' we assign to the area a single value, in most cases a variable value of the area. But this method is demanding on calculation, and therefore, we try to approximate area sampling by several point samples, and then to average them.
Sampling applet. Author Štulrajterová Paulína