As one of the most popular methods for noise removal
there is method of convolution. The principle of this method
is in the use of mask (a matrix of dimension two) which
with its coefficients determines what role a fixed pixel will
have. Already this sentence suggests that convolution is
actually averaging of values with which we deliberately
distort the image in order to reduce the volume of noise
pixels. Convulution principle is illustrated in (Figure 1) .