LITERATURE SURVEY OF AUTOMATIC FACE RECOGNITION ...

The algorithm has three main purposes:
(a) To remove impulse noise.
CHAPTER XX
HOW IT WORKS
(b) To provide smoothing of other noise that may not be impulsive.
(c) To reduce excessive distortions such as too much thinning or thickening of
object boundaries.
The steps are follows:
Step 1 Initialization
Start with the smallest windows size S = 3. Let the maximum window size
be Smax (again, an odd number).
Step 2 Computation of order statistic
Let Zmin = S (0) ([Sk,l]) be the output of the 0­th order statistic filter. Zmax =
S(N)([wk,l]) is the output of the N­th order statistic filter and Zmed =S((N+1)/2)
([wk,l]) is the output of the median filter.
Step 3 Evaluation of the terminating condition
If the condition Zmin < Zmed < Zmax is satisfied then the processing ends with
the computation of the output value which is defined as follows: If Zmin < Zxy < Zmax
then the pixel is not corrupted by noise and the output value is the value of the
original pixel, i.e. Zxy = Zxy. If Zmin < Zxy < Zmax is not satisfied then the output value
is the median of the window, i.e. yuv = Zmed. If the condition is not satisfied then
the computation continues.
Step 4 Increasing of the window size
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