text: //////////////////////////////////////////////////////////////////////////
  //
  //  Copyright (c) 2013, Image Engine Design Inc. All rights reserved.
  //
  //  Redistribution and use in source and binary forms, with or without
  //  modification, are permitted provided that the following conditions are
  //  met:
  //
  //      * Redistributions of source code must retain the above
  //        copyright notice, this list of conditions and the following
  //        disclaimer.
  //
  //      * Redistributions in binary form must reproduce the above
  //        copyright notice, this list of conditions and the following
  //        disclaimer in the documentation and/or other materials provided with
  //        the distribution.
  //
  //      * Neither the name of John Haddon nor the names of
  //        any other contributors to this software may be used to endorse or
  //        promote products derived from this software without specific prior
  //        written permission.
  //
  //  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  //  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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  //
  //////////////////////////////////////////////////////////////////////////
  
  #ifndef GAFFERIMAGE_IMAGESTATS_H
  #define GAFFERIMAGE_IMAGESTATS_H
  
  #include "GafferImage/ImagePlug.h"
  
  #include "Gaffer/BoxPlug.h"
  #include "Gaffer/CompoundNumericPlug.h"
  #include "Gaffer/ComputeNode.h"
  
  namespace GafferImage
  {
  
  /// \todo Add an areaSource plug with the same semantics
  /// that the Crop node has.
  class GAFFERIMAGE_API ImageStats : public Gaffer::ComputeNode
  {
  
  	public :
  
  		ImageStats( const std::string &name=staticTypeName() );
  		~ImageStats() override;
  
  		GAFFER_GRAPHCOMPONENT_DECLARE_TYPE( GafferImage::ImageStats, ImageStatsTypeId, Gaffer::ComputeNode );
  
  		void affects( const Gaffer::Plug *input, AffectedPlugsContainer &outputs ) const override;
  
  		GafferImage::ImagePlug *inPlug();
  		const GafferImage::ImagePlug *inPlug() const;
  
  		Gaffer::StringVectorDataPlug *channelsPlug();
  		const Gaffer::StringVectorDataPlug *channelsPlug() const;
  
  		Gaffer::Box2iPlug *areaPlug();
  		const Gaffer::Box2iPlug *areaPlug() const;
  
  		Gaffer::Color4fPlug *averagePlug();
  		const Gaffer::Color4fPlug *averagePlug() const;
  
  		Gaffer::Color4fPlug *minPlug();
  		const Gaffer::Color4fPlug *minPlug() const;
  
  		Gaffer::Color4fPlug *maxPlug();
  		const Gaffer::Color4fPlug *maxPlug() const;
  
  	protected :
  
  		/// Implemented to hash the area we are sampling along with the channel context and regionOfInterest.
  		void hash( const Gaffer::ValuePlug *output, const Gaffer::Context *context, IECore::MurmurHash &h ) const override;
  
  		/// Computes the min, max and average plugs by analyzing the input ImagePlug.
  		void compute( Gaffer::ValuePlug *output, const Gaffer::Context *context ) const override;
  
  	private :
  
  		std::string channelName( int colorIndex ) const;
  
  		static size_t g_firstPlugIndex;
  
  };
  
  IE_CORE_DECLAREPTR( ImageStats );
  
  } // namespace GafferImage
  
  #endif // GAFFERIMAGE_IMAGESTATS_H
  