
histogram h
2
z
i
ðÞ. The input image can be modified according to the equalization
transformation, T, given in Eq. 6.5, to produce a flat histogram. Further,
the transformation, V, will give the target image a flat distribution if
Vz
i
ðÞ¼
X
i
j¼0
h
2
z
j
and Tr
i
ðÞ¼
X
i
j¼0
h
1
r
j
i ¼ 0, 1, ..., L 1(6:6)
Then the output image, g(x, y), can be computed from the input image, f (x, y),
using the following cascaded transformation:
gx, yðÞ¼V
1
Tfx, yðÞðÞ½ (6:7)
This transformation enables us to obtain an output image with the desired
gray-level distribution, h
2
z
i
ðÞ.
6.2.6 Spatial Filtering
Spatial filtering involves the convolution of an image with a specific kernel
operator. ...