// =========================================================================
// @author Leonardo Florez Valencia
// @email florez-l@javeriana.edu.co
// =========================================================================
#ifndef __fpa__Filters__Image__SeedsFromLabelsInterface__hxx__
#define __fpa__Filters__Image__SeedsFromLabelsInterface__hxx__

#include <itkImage.h>
#include <itkImageRegionConstIteratorWithIndex.h>

// -------------------------------------------------------------------------
template< class _TTraits >
fpa::Filters::Image::SeedsFromLabelsInterface< _TTraits >::
SeedsFromLabelsInterface( itk::ProcessObject* f )
  : Superclass( f )
{
}

// -------------------------------------------------------------------------
template< class _TTraits >
fpa::Filters::Image::SeedsFromLabelsInterface< _TTraits >::
~SeedsFromLabelsInterface( )
{
}

// -------------------------------------------------------------------------
template< class _TTraits >
void fpa::Filters::Image::SeedsFromLabelsInterface< _TTraits >::
_PrepareSeeds( const itk::DataObject* reference )
{
  // Input object is a labelled image?
  typedef typename _TTraits::TMark _TMark;
  typedef itk::Image< _TMark, _TTraits::Dimension > _TLabelImage;
  const _TLabelImage* labels =
    dynamic_cast< const _TLabelImage* >( reference );
  if( labels != NULL )
  {
    this->m_UnifiedSeeds.clear( );

    // Iterate over labels
    typedef itk::ImageRegionConstIteratorWithIndex< _TLabelImage > _TIt;
    typename _TLabelImage::RegionType reg = labels->GetRequestedRegion( );
    _TIt lIt( labels, reg );
    for( lIt.GoToBegin( ); !lIt.IsAtEnd( ); ++lIt )
    {
      if( lIt.Get( ) > 0 )
      {
        bool is_seed = false;
        for( unsigned int d = 0; d < _TTraits::Dimension; ++d )
        {
          for( int s = -1; s <= 1; s += 2 )
          {
            TVertex neigh = lIt.GetIndex( );
            neigh[ d ] += s;
            if( reg.IsInside( neigh ) )
              is_seed |= ( labels->GetPixel( neigh ) == 0 );

          } // rof

        } // rof

        // Add pixel as seed or already marked
        TNode node;
        node.Vertex = lIt.GetIndex( );
        node.Parent = lIt.GetIndex( );
        node.FrontId = TMark( lIt.Get( ) );
        node.Value = TOutputValue( lIt.Get( ) );
        if( !is_seed )
        {
          this->_AssignOutputValue( node );
          this->_Mark( node );
        }
        else
          this->m_UnifiedSeeds.insert( node );

      } // fi

    } // rof

  } // fi
}

#endif // __fpa__Filters__Image__SeedsFromLabelsInterface__hxx__
// eof - $RCSfile$