1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
This example illustrates the use of the :doxygen:`FrostImageFilter`.
This filter belongs to the family of the edge-preserving smoothing
filters which are usually used for speckle reduction in radar
images.
This filter uses a negative exponential convolution kernel.
The output of the filter for pixel p is:
.. math::
\hat I_{s}=\sum_{p\in\eta_{p}} m_{p}I_{p}
m_{p}=\frac{KC_{s}^{2}\exp(-KC_{s}^{2}d_{s, p})}{\sum_{p\in\eta_{p}} KC_{s}^{2}\exp(-KC_{s}^{2}d_{s, p})}
d_{s, p}=\sqrt{(i-i_{p})^2+(j-j_{p})^2}
where:
* :math:`K`: the decrease coefficient
* :math:`(i, j)`: the coordinates of the pixel inside the region defined by :math:`\eta_{s}`
* :math:`(i_{p}, j_{p})`: the coordinates of the pixels belonging to :math:`\eta_{p} \subset \eta_{s}`
* :math:`C_{s}`: the variation coefficient computed over :math:`\eta_{p}`
.. |image1| image:: /Input/GomaSmall.png
.. |image2| image:: /Output/GomaSmallFrostFiltered.png
.. _Figure1:
+--------------------------+-------------------------+
| |image1| | |image2| |
+--------------------------+-------------------------+
Result of applying the FrostImageFilter to a SAR image.
|
