-
Notifications
You must be signed in to change notification settings - Fork 0
/
itkShotNoiseImageFilter.txx
107 lines (90 loc) · 3.5 KB
/
itkShotNoiseImageFilter.txx
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
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: $RCSfile: $
Language: C++
Date: $Date: $
Version: $Revision: $
Author: Gavin Baker <gavinb@cs.mu.oz.au>
Copyright (c) 2004 Insight Software Consortium. All rights reserved.
See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#include "itkShotNoiseImageFilter.h"
#include "itkThreadSafeMersenneTwisterRandomVariateGenerator.h"
#include "itkImageRegionIterator.h"
#include "itkImageRegionConstIterator.h"
#include "itkProgressReporter.h"
#include "itkNormalVariateGenerator.h"
namespace itk
{
template <class TInputImage, class TOutputImage>
ShotNoiseImageFilter<TInputImage, TOutputImage>
::ShotNoiseImageFilter()
{
m_Scale = 1.0;
}
template <class TInputImage, class TOutputImage>
void
ShotNoiseImageFilter<TInputImage, TOutputImage>
::ThreadedGenerateData( const OutputImageRegionType &outputRegionForThread,
ThreadIdType threadId)
{
InputImageConstPointer inputPtr = this->GetInput();
OutputImagePointer outputPtr = this->GetOutput(0);
// create a random generator per thread
typename Statistics::ThreadSafeMersenneTwisterRandomVariateGenerator::Pointer rand =
Statistics::ThreadSafeMersenneTwisterRandomVariateGenerator::New();
rand->Initialize();
typename Statistics::NormalVariateGenerator::Pointer randn = Statistics::NormalVariateGenerator::New();
// Define the portion of the input to walk for this thread, using
// the CallCopyOutputRegionToInputRegion method allows for the input
// and output images to be different dimensions
InputImageRegionType inputRegionForThread;
this->CallCopyOutputRegionToInputRegion(inputRegionForThread, outputRegionForThread);
// Define the iterators
ImageRegionConstIterator<TInputImage> inputIt(inputPtr, inputRegionForThread);
ImageRegionIterator<TOutputImage> outputIt(outputPtr, outputRegionForThread);
ProgressReporter progress(this, threadId, outputRegionForThread.GetNumberOfPixels());
inputIt.GoToBegin();
outputIt.GoToBegin();
while( !inputIt.IsAtEnd() )
{
double in = m_Scale * inputIt.Get();
if( in < 50 )
{
double L = vcl_exp( -in );
long k = 0;
double p = 1.0;
do
{
k += 1;
p *= rand->GetVariate();
}
while( p > L );
// clip the output to the actual supported range
outputIt.Set( (OutputImagePixelType) std::min( (double)NumericTraits<OutputImagePixelType>::max(), (k-1)/m_Scale ) );
}
else
{
double out = in + vcl_sqrt( in ) * randn->GetVariate();
outputIt.Set( (OutputImagePixelType) std::min( (double)NumericTraits<OutputImagePixelType>::max(), out/m_Scale ) );
}
++inputIt;
++outputIt;
progress.CompletedPixel(); // potential exception thrown here
}
}
template <class TInputImage, class TOutputImage>
void
ShotNoiseImageFilter<TInputImage, TOutputImage>
::PrintSelf(std::ostream& os,
Indent indent) const
{
Superclass::PrintSelf(os, indent);
os << indent << "Scale: "
<< static_cast<typename NumericTraits<double>::PrintType>(this->GetScale())
<< std::endl;
}
} /* namespace itk */