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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkGradientDifferenceImageToImageMetricTest.cxx,v $
  Language:  C++
  Date:      $Date: 2005/12/01 18:43:07 $
  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

#include "itkGradientDifferenceImageToImageMetric.h"
#include "itkGaussianImageSource.h"
#include "itkImage.h"
#include "itkLinearInterpolateImageFunction.h"
#include "itkMeanSquaresHistogramImageToImageMetric.h"
#include "itkTranslationTransform.h"


int itkGradientDifferenceImageToImageMetricTest(int , char*[] )
{
  // Create two simple images.
  const unsigned int ImageDimension = 2;
  typedef double PixelType;
  typedef double CoordinateRepresentationType;
    
  //Allocate Images
  typedef itk::Image<PixelType,ImageDimension> MovingImageType;
  typedef itk::Image<PixelType,ImageDimension> FixedImageType;
    
  // Declare Gaussian Sources
  typedef itk::GaussianImageSource<MovingImageType> MovingImageSourceType;
  typedef itk::GaussianImageSource<FixedImageType> FixedImageSourceType;
  typedef MovingImageSourceType::Pointer MovingImageSourcePointer;
  typedef FixedImageSourceType::Pointer FixedImageSourcePointer;
    
  // Note: the following declarations are classical arrays
  unsigned long fixedImageSize[] = {100,  100};
  unsigned long movingImageSize[] = {100,  100}; 
    
  float fixedImageSpacing[]  = {1.0f, 1.0f}; 
  float movingImageSpacing[] = {1.0f, 1.0f}; 
    
  float fixedImageOrigin[] = {0.0f, 0.0f}; 
  float movingImageOrigin[] = {0.0f, 0.0f}; 
    
  MovingImageSourceType::Pointer movingImageSource =
    MovingImageSourceType::New();
  FixedImageSourceType::Pointer  fixedImageSource  =
    FixedImageSourceType::New();
    
  movingImageSource->SetSize(movingImageSize);
  movingImageSource->SetOrigin(movingImageOrigin);
  movingImageSource->SetSpacing(movingImageSpacing);
  movingImageSource->SetNormalized(false);
  movingImageSource->SetScale(200.0f);
    
  fixedImageSource->SetSize(fixedImageSize);
  fixedImageSource->SetOrigin(fixedImageOrigin);
  fixedImageSource->SetSpacing(fixedImageSpacing);
  fixedImageSource->SetNormalized(false);
  fixedImageSource->SetScale(200.0f);
    
  movingImageSource->Update(); // Force the filter to run
  fixedImageSource->Update();  // Force the filter to run
    
  MovingImageType::Pointer movingImage = movingImageSource->GetOutput();
  FixedImageType::Pointer  fixedImage  = fixedImageSource->GetOutput();
    
  // Set up the metric.
  typedef itk::GradientDifferenceImageToImageMetric<
                                            FixedImageType,
                                            MovingImageType> MetricType;
    
  typedef MetricType::TransformType TransformBaseType;
  typedef MetricType::DerivativeType DerivativeType;
  typedef TransformBaseType::ParametersType ParametersType;
    
  MetricType::Pointer metric = MetricType::New();
    
  // Plug the images into the metric.
  metric->SetFixedImage(fixedImage);
  metric->SetMovingImage(movingImage);

  // Set up a transform.
  typedef itk::TranslationTransform<CoordinateRepresentationType,
    ImageDimension> TransformType;
    
  TransformType::Pointer transform = TransformType::New();
  metric->SetTransform(transform.GetPointer());
    
  // Set up an interpolator.
  typedef itk::LinearInterpolateImageFunction<MovingImageType,
    double> InterpolatorType;
    
  InterpolatorType::Pointer interpolator = InterpolatorType::New();
  interpolator->SetInputImage(movingImage.GetPointer());
  metric->SetInterpolator(interpolator.GetPointer());
    
  // Define the region over which the metric will be computed.
  metric->SetFixedImageRegion(fixedImage->GetBufferedRegion());

  // Set up transform parameters.
  const unsigned int numberOfParameters = transform->GetNumberOfParameters();

  ParametersType parameters( numberOfParameters );
  for (unsigned int k = 0; k < numberOfParameters; k++)
    {
    parameters[k] = 0.0;
    }


  try
    {
    // Initialize the metric.
    metric->Initialize();

    // Do some work
    DerivativeType derivatives( numberOfParameters );
    MetricType::MeasureType value;
    for (double y = -10.0; y <= 10.0; y += 5.0)
      {
      parameters[1] = y;
      for (double x = -10.0; x <= 10.0; x += 5.0)
        {
        parameters[0] = x;
        metric->GetValueAndDerivative (parameters, value, derivatives);
        std::cout << "Parameters: " << parameters
                  << ", Value: " << value 
                  << ", Derivatives: " << derivatives << std::endl;
        }
      }

    // Exercise Print() method.
    metric->Print(std::cout);

    std::cout << "Test passed." << std::endl;
    }
  catch (itk::ExceptionObject& ex)
    {
    std::cerr << "Exception caught!" << std::endl;
    std::cerr << ex << std::endl;
    return EXIT_FAILURE;
    }

  return EXIT_SUCCESS;
}
