/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: SpatialObjectToImageStatisticsCalculator.cxx,v $
  Language:  C++
  Date:      $Date: 2005/12/10 17:10:51 $
  Version:   $Revision: 1.4 $

  Copyright (c) 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.

=========================================================================*/
#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#endif

// 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
#include "itkSpatialObjectToImageStatisticsCalculator.h"
// Software Guide : EndCodeSnippet

#include "itkImage.h"
#include "itkEllipseSpatialObject.h"
#include "itkRandomImageSource.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();
  unsigned long size[2];
  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
  typedef itk::SpatialObjectToImageStatisticsCalculator< 
    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;
}
