Generic gaussian model estimator added

[cpPlugins.git] / appli / examples / example_ImageGaussianModelEstimator.cxx

diff --git a/appli/examples/example_ImageGaussianModelEstimator.cxx b/appli/examples/example_ImageGaussianModelEstimator.cxx
new file mode 100644 (file)
index 0000000..0187f2a
--- /dev/null
+++ b/appli/examples/example_ImageGaussianModelEstimator.cxx
@@ -0,0 +1,85 @@
+#include <cstdlib>
+#include <iostream>
+#include <string>
+
+#include <itkImage.h>
+#include <itkImageFileReader.h>
+#include <itkImageRegionConstIterator.h>
+#include <itkMatrix.h>
+#include <itkRGBPixel.h>
+#include <itkVector.h>
+
+#include <cpPlugins/Extensions/Algorithms/IterativeGaussianModelEstimator.h>
+
+// -------------------------------------------------------------------------
+const unsigned int Dim = 2;
+typedef double                    TScalar;
+typedef unsigned char             TChannel;
+typedef itk::RGBPixel< TChannel > TPixel;
+typedef itk::Image< TPixel, Dim > TImage;
+
+// -------------------------------------------------------------------------
+int main( int argc, char* argv[] )
+{
+  if( argc < 2 )
+  {
+    std::cerr
+      << "Usage: " << argv[ 0 ]
+      << " input_image" << std::endl;
+    return( 1 );
+
+  } // fi
+  std::string input_image_file = argv[ 1 ];
+
+  // Read image
+  itk::ImageFileReader< TImage >::Pointer reader =
+    itk::ImageFileReader< TImage >::New( );
+  reader->SetFileName( input_image_file );
+  try
+  {
+    reader->Update( );
+  }
+  catch( itk::ExceptionObject& err )
+  {
+    std::cerr << "Error caught: " << err << std::endl;
+    return( 1 );
+
+  } // yrt
+  TImage::ConstPointer input_image = reader->GetOutput( );
+
+  // Compute gaussian model
+  typedef cpPlugins::Extensions::Algorithms::IterativeGaussianModelEstimator< TScalar, 3 > TEstimator;
+
+  TEstimator::Pointer estimator = TEstimator::New( );
+  estimator->Clear( );
+
+  itk::ImageRegionConstIterator< TImage > it(
+    input_image,
+    input_image->GetRequestedRegion( )
+    );
+  for( it.GoToBegin( ); !it.IsAtEnd( ); ++it )
+  {
+    estimator->AddSample(
+      TScalar( it.Get( ).GetRed( ) ),
+      TScalar( it.Get( ).GetGreen( ) ),
+      TScalar( it.Get( ).GetBlue( ) )
+      );
+
+  } // rof
+
+  itk::Vector< TScalar, 3 > mean;
+  itk::Matrix< TScalar, 3, 3 > cova;
+
+  estimator->GetModel( mean, cova );
+  std::cout
+    << "Covariance = " << std::endl << cova << std::endl;
+  std::cout
+    << "Inverse covariance = "
+    << std::endl << cova.GetInverse( ) << std::endl;
+  std::cout
+    << "Mean = " << std::endl << mean << std::endl;
+
+  return( 0 );
+}
+
+// eof - $RCSfile$