ITK  4.6.0
Insight Segmentation and Registration Toolkit
SpatialObjects/SpatialObjectToImageStatisticsCalculator.cxx
/*=========================================================================
*
* 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.
*
*=========================================================================*/
// Software Guide : BeginLatex
//
// \index{itk::Spatial\-Object\-To\-Image\-Statistics\-Calculator}
// This example describes how to use the
// \doxygen{SpatialObjectToImageStatisticsCalculator} to compute statistics
// of an \doxygen{Image} only in a region defined inside a given \doxygen{SpatialObject}.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
#include "itkImage.h"
int main(int, char * [] )
{
// Software Guide : BeginLatex
// We first create a test image using the \doxygen{RandomImageSource}
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::Image< unsigned char, 2 > ImageType;
typedef itk::RandomImageSource< ImageType > RandomImageSourceType;
RandomImageSourceType::Pointer randomImageSource
= RandomImageSourceType::New();
size[0] = 10;
size[1] = 10;
randomImageSource->SetSize(size);
randomImageSource->Update();
ImageType::Pointer image = randomImageSource->GetOutput();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
// Next we create an \doxygen{EllipseSpatialObject} with a radius of 2.
// We also move the ellipse to the center of the image by increasing
// the offset of the IndexToObjectTransform.
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::EllipseSpatialObject<2> EllipseType;
EllipseType::Pointer ellipse = EllipseType::New();
ellipse->SetRadius(2);
EllipseType::VectorType offset;
offset.Fill(5);
ellipse->GetIndexToObjectTransform()->SetOffset(offset);
ellipse->ComputeObjectToParentTransform();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
// Then we can create the \doxygen{SpatialObjectToImageStatisticsCalculator}
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
ImageType, EllipseType > CalculatorType;
CalculatorType::Pointer calculator = CalculatorType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
// We pass a pointer to the image to the calculator.
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
calculator->SetImage(image);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
// And we also pass the SpatialObject. The statistics will be computed inside the SpatialObject
// (Internally the calculator is using the \code{IsInside()} function).
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
calculator->SetSpatialObject(ellipse);
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
// At the end we trigger the computation via the \code{Update()} function and we
// can retrieve the mean and the covariance matrix using \code{GetMean()} and \code{GetCovarianceMatrix()}
// respectively.
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
calculator->Update();
std::cout << "Sample mean = " << calculator->GetMean() << std::endl;
std::cout << "Sample covariance = " << calculator->GetCovarianceMatrix();
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}