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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
#include "itkImage.h"
#include "itkImageFileReader.h"
// Software Guide : BeginLatex
//
// Thanks to the flexibility offered by the
// \href{http://www.boost.org/more/generic_programming.html}{Generic
// Programming} style on which ITK is based, it is possible to
// instantiate images of arbitrary pixel type. The following example
// illustrates how a color image with RGB pixels can be defined.
//
// A class intended to support the RGB pixel type is available in ITK. You
// could also define your own pixel class and use it to instantiate a
// custom image type. In order to use the \doxygen{RGBPixel} class, it is
// necessary to include its header file.
//
// \index{itk::RGBPixel}
// \index{itk::RGBPixel!Image}
// \index{itk::RGBPixel!header}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "itkRGBPixel.h"
// Software Guide : EndCodeSnippet
int main( int , char * argv[] )
{
// Software Guide : BeginLatex
//
// The RGB pixel class is templated over a type used to represent each one
// of the red, green and blue pixel components. A typical instantiation of the
// templated class is as follows.
//
// \index{itk::RGBPixel!Instantiation}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::RGBPixel< unsigned char > PixelType;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The type is then used as the pixel template parameter of the image.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::Image< PixelType, 3 > ImageType;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The image type can be used to instantiate other filter, for example,
// an \doxygen{ImageFileReader} object that will read the image from a
// file.
//
// \index{itk::ImageFileReader!RGB Image}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::ImageFileReader< ImageType > ReaderType;
// Software Guide : EndCodeSnippet
ReaderType::Pointer reader = ReaderType::New();
const char * const filename = argv[1];
reader->SetFileName( filename );
reader->Update();
ImageType::Pointer image = reader->GetOutput();
const ImageType::IndexType pixelIndex = {{25,35,0}};
// Software Guide : BeginLatex
//
// Access to the color components of the pixels can now be performed using
// the methods provided by the RGBPixel class.
//
// \index{itk::Image!GetPixel()}
// \index{itk::RGBPixel!GetRed()}
// \index{itk::RGBPixel!GetGreen()}
// \index{itk::RGBPixel!GetBlue()}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
PixelType onePixel = image->GetPixel( pixelIndex );
PixelType::ValueType red = onePixel.GetRed();
PixelType::ValueType green = onePixel.GetGreen();
PixelType::ValueType blue = onePixel.GetBlue();
// Software Guide : EndCodeSnippet
std::cout << "Pixel values from GetRed,GetGreen,GetBlue:" << std::endl;
std::cout << "Red = "
<< itk::NumericTraits<PixelType::ValueType>::PrintType(red)
<< std::endl;
std::cout << "Green = "
<< itk::NumericTraits<PixelType::ValueType>::PrintType(green)
<< std::endl;
std::cout << "Blue = "
<< itk::NumericTraits<PixelType::ValueType>::PrintType(blue)
<< std::endl;
// Software Guide : BeginLatex
//
// The subindex notation can also be used since the \doxygen{RGBPixel}
// inherits the \code{[]} operator from the \doxygen{FixedArray} class.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
red = onePixel[0]; // extract Red component
green = onePixel[1]; // extract Green component
blue = onePixel[2]; // extract Blue component
std::cout << "Pixel values:" << std::endl;
std::cout << "Red = "
<< itk::NumericTraits<PixelType::ValueType>::PrintType(red)
<< std::endl;
std::cout << "Green = "
<< itk::NumericTraits<PixelType::ValueType>::PrintType(green)
<< std::endl;
std::cout << "Blue = "
<< itk::NumericTraits<PixelType::ValueType>::PrintType(blue)
<< std::endl;
// Software Guide : EndCodeSnippet
// Lets repeat that both \code{SetPixel()} and \code{GetPixel()} are
// inefficient and should only be used for debugging purposes or for
// implementing interactions with a graphical user interface such as
// querying pixel value by clicking with the mouse.
//
return EXIT_SUCCESS;
}
|
