// -------------------------------------------------------------------------
// @author Leonardo Florez-Valencia (florez-l@javeriana.edu.co)
// -------------------------------------------------------------------------

#ifndef __CPEXTENSIONS__ALGORITHMS__MULTISCALEGAUSSIANIMAGEFILTER__H__
#define __CPEXTENSIONS__ALGORITHMS__MULTISCALEGAUSSIANIMAGEFILTER__H__

#include <set>
#include <itkImageToImageFilter.h>

namespace cpExtensions
{
  namespace Algorithms
  {
    /**
     */
    template< class I, class O >
    class MultiScaleGaussianImageFilter
      : public itk::ImageToImageFilter< I, O >
    {
    public:
      typedef MultiScaleGaussianImageFilter   Self;
      typedef itk::ImageToImageFilter< I, O > Superclass;
      typedef itk::SmartPointer< Self >       Pointer;
      typedef itk::SmartPointer< const Self > ConstPointer;

      typedef I TInputImage;
      typedef O TOutputImage;

      typedef std::set< double > TScalesContainer;

      enum FilterId
      {
        Gradient = 0,
        GradientMagnitude,
        Hessian,
        None
      };

    protected:
      /**
       */
      class _Greater
      {
      public:
        typedef typename O::PixelType _T;

      public:
        _Greater( );
        virtual ~_Greater( );
        bool operator!=( const _Greater& b ) const;
        bool operator==( const _Greater& b ) const;
        inline _T operator()( const _T& a ) const;
        inline _T operator()( const _T& a, const _T& b ) const;
      };

    public:
      itkNewMacro( Self );
      itkTypeMacro( MultiScaleGaussianImageFilter, itkImageToImageFilter );

    public:
      void SetFilterToGradient( );
      void SetFilterToGradientMagnitude( );
      void SetFilterToHessian( );

      bool IsGradientFilter( ) const;
      bool IsGradientMagnitudeFilter( ) const;
      bool IsHessianFilter( ) const;

      void AddScale( const double& s );
      unsigned long GetNumberOfScales( ) const;

    protected:
      MultiScaleGaussianImageFilter( );
      virtual ~MultiScaleGaussianImageFilter( );

      virtual void GenerateData( );

      template< class F >
      void _GenerateData( );

    private:
      // Purposely not implemented.
      MultiScaleGaussianImageFilter( const Self& );
      void operator=( const Self& );

    protected:
      TScalesContainer m_Scales;
      FilterId m_FilterId;
    };

  } // ecapseman

} // ecapseman

#include <cpExtensions/Algorithms/MultiScaleGaussianImageFilter.hxx>

#endif // __CPEXTENSIONS__ALGORITHMS__MULTISCALEGAUSSIANIMAGEFILTER__H__

// eof - $RCSfile$