1 /*=========================================================================
2
3 Program: Visualization Toolkit
4 Module: vtkImageRGBToHSI.cxx
5
6 Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
7 All rights reserved.
8 See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
9
10 This software is distributed WITHOUT ANY WARRANTY; without even
11 the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
12 PURPOSE. See the above copyright notice for more information.
13
14 =========================================================================*/
15 #include "vtkImageRGBToHSI.h"
16
17 #include "vtkMath.h"
18 #include "vtkImageData.h"
19 #include "vtkImageProgressIterator.h"
20 #include "vtkObjectFactory.h"
21
22 #include <math.h>
23
24 vtkStandardNewMacro(vtkImageRGBToHSI);
25
26 //----------------------------------------------------------------------------
vtkImageRGBToHSI()27 vtkImageRGBToHSI::vtkImageRGBToHSI()
28 {
29 this->Maximum = 255.0;
30 this->SetNumberOfInputPorts(1);
31 this->SetNumberOfOutputPorts(1);
32 }
33
34 //----------------------------------------------------------------------------
35 // This templated function executes the filter for any type of data.
36 template <class T>
vtkImageRGBToHSIExecute(vtkImageRGBToHSI * self,vtkImageData * inData,vtkImageData * outData,int outExt[6],int id,T *)37 void vtkImageRGBToHSIExecute(vtkImageRGBToHSI *self,
38 vtkImageData *inData,
39 vtkImageData *outData,
40 int outExt[6], int id, T *)
41 {
42 vtkImageIterator<T> inIt(inData, outExt);
43 vtkImageProgressIterator<T> outIt(outData, outExt, self, id);
44 int idxC, maxC;
45 double R, G, B, H, S, I;
46 double max = self->GetMaximum();
47 double temp;
48
49 // find the region to loop over
50 maxC = inData->GetNumberOfScalarComponents()-1;
51
52 // Loop through output pixels
53 while (!outIt.IsAtEnd())
54 {
55 T* inSI = inIt.BeginSpan();
56 T* outSI = outIt.BeginSpan();
57 T* outSIEnd = outIt.EndSpan();
58 while (outSI != outSIEnd)
59 {
60 // Pixel operation
61 R = static_cast<double>(*inSI); inSI++;
62 G = static_cast<double>(*inSI); inSI++;
63 B = static_cast<double>(*inSI); inSI++;
64 // Saturation
65 temp = R;
66 if (G < temp)
67 {
68 temp = G;
69 }
70 if (B < temp)
71 {
72 temp = B;
73 }
74 double sumRGB = R+G+B;
75 if(sumRGB == 0.0)
76 {
77 S = 0.0;
78 }
79 else
80 {
81 S = max * (1.0 - (3.0 * temp / sumRGB));
82 }
83
84 temp = static_cast<double>(R + G + B);
85 // Intensity is easy
86 I = temp / 3.0;
87
88 // Hue
89 temp = sqrt((R-G)*(R-G) + (R-B)*(G-B));
90 if(temp != 0.0)
91 {
92 temp = acos((0.5 * ((R-G) + (R-B))) / temp);
93 }
94 if (G >= B)
95 {
96 H = max * (temp / (2.0 * vtkMath::Pi()));
97 }
98 else
99 {
100 H = max * (1.0 - (temp / (2.0 * vtkMath::Pi())));
101 }
102
103 // assign output.
104 *outSI = static_cast<T>(H); outSI++;
105 *outSI = static_cast<T>(S); outSI++;
106 *outSI = static_cast<T>(I); outSI++;
107
108 for (idxC = 3; idxC <= maxC; idxC++)
109 {
110 *outSI++ = *inSI++;
111 }
112 }
113 inIt.NextSpan();
114 outIt.NextSpan();
115 }
116 }
117
118 //----------------------------------------------------------------------------
ThreadedExecute(vtkImageData * inData,vtkImageData * outData,int outExt[6],int id)119 void vtkImageRGBToHSI::ThreadedExecute (vtkImageData *inData,
120 vtkImageData *outData,
121 int outExt[6], int id)
122 {
123 vtkDebugMacro(<< "Execute: inData = " << inData
124 << ", outData = " << outData);
125
126 // this filter expects that input is the same type as output.
127 if (inData->GetScalarType() != outData->GetScalarType())
128 {
129 vtkErrorMacro(<< "Execute: input ScalarType, " << inData->GetScalarType()
130 << ", must match out ScalarType " << outData->GetScalarType());
131 return;
132 }
133
134 // need three components for input and output
135 if (inData->GetNumberOfScalarComponents() < 3)
136 {
137 vtkErrorMacro("Input has too few components");
138 return;
139 }
140 if (outData->GetNumberOfScalarComponents() < 3)
141 {
142 vtkErrorMacro("Output has too few components");
143 return;
144 }
145
146 switch (inData->GetScalarType())
147 {
148 vtkTemplateMacro(
149 vtkImageRGBToHSIExecute( this, inData,
150 outData, outExt, id,
151 static_cast<VTK_TT *>(0)));
152 default:
153 vtkErrorMacro(<< "Execute: Unknown ScalarType");
154 return;
155 }
156 }
157
PrintSelf(ostream & os,vtkIndent indent)158 void vtkImageRGBToHSI::PrintSelf(ostream& os, vtkIndent indent)
159 {
160 this->Superclass::PrintSelf(os,indent);
161
162 os << indent << "Maximum: " << this->Maximum << "\n";
163 }
164
165