August 2015
Intermediate to advanced
242 pages
7h 33m
English
Content preview from Touchless Fingerprint Biometrics
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52
Touchless Fingerprint Biometrics
proposed in [168]. The algorithm described in [168] is one of the most commonly
used preprocessing techniques and is based on the following formula:
I
(x, y) =
⎧
⎪
⎪
⎪
⎨
⎪
⎪
⎪
⎩
μ
0
+
(I(x, y) − μ)σ
0
σ
if I (x, y)>μ,
μ
0
−
(I(x, y) − μ)σ
0
σ
otherwise,
(4.2)
where μ
0
and σ
0
are the desired mean and standard deviation, respectively, of the
normalized image I
,andμ and σ are the mean and standard deviation, respectively,
of image I .
The contextual filtering techniques are the most commonly used in the liter-
ature. These techniques change the characteristics of the filter used for enhancing
different fingerprint regions according to the local ...