/********************************************************************
**                Image Component Library (ICL)                    **
**                                                                 **
** Copyright (C) 2006-2012 CITEC, University of Bielefeld          **
**                         Neuroinformatics Group                  **
** Website: www.iclcv.org and                                      **
**          http://opensource.cit-ec.de/projects/icl               **
**                                                                 **
** File   : include/ICLBlob/VQ2D.h                                 **
** Module : ICLBlob                                                **
** Authors: Christof Elbrechter                                    **
**                                                                 **
**                                                                 **
** Commercial License                                              **
** ICL can be used commercially, please refer to our website       **
** www.iclcv.org for more details.                                 **
**                                                                 **
** GNU General Public License Usage                                **
** Alternatively, this file may be used under the terms of the     **
** GNU General Public License version 3.0 as published by the      **
** Free Software Foundation and appearing in the file LICENSE.GPL  **
** included in the packaging of this file.  Please review the      **
** following information to ensure the GNU General Public License  **
** version 3.0 requirements will be met:                           **
** http://www.gnu.org/copyleft/gpl.html.                           **
**                                                                 **
** The development of this software was supported by the           **
** Excellence Cluster EXC 277 Cognitive Interaction Technology.    **
** The Excellence Cluster EXC 277 is a grant of the Deutsche       **
** Forschungsgemeinschaft (DFG) in the context of the German       **
** Excellence Initiative.                                          **
**                                                                 **
*********************************************************************/

#ifndef VQ2D_H
#define VQ2D_H

#include <stdlib.h>
#include <ICLBlob/VQVectorSet.h>
#include <ICLBlob/VQClusterInfo.h>
#include <ICLCore/Mathematics.h>
#include <ICLUtils/Time.h>

namespace icl{
  /// Support class for 2-Dimensional vector quatisation using KMeans \ingroup G_UTILS
  /** Vector Quantisation is internally applied using the <b>KMeans</b> algorithm
      which can be defines as follows:
      
      <pre>
      Given data set D of |D| elements with D = d_1,...,d_|D|
      Given center count K with 
      Optionally given data set C = c1,..,cK of initial centers (prototypes) of size |C|=K
      
      algorithm:
      
      for i = 1 to MAX-STEPS do
         for k = 1 to K
            Vc : = { di | |di-ck| < |di-co| for all o!=k } ( Voronoi cell for center c )
         endfor

         for k = 1 to K
            ck := mean(Vc)
         endfor
      
         // current quatisation is given by the set of centers C
         
         if current quatisation error < minError 
            break
         endif
      endfor
      </pre>
      
  **/
  class VQ2D{
    public:
    
    /// create a new VQ
    VQ2D(float *data=0, int dim=0, bool deepCopyData = false);
    
    /// data will be copied once
    void setData(float *data, int dim, bool deepCopy = false);
    
    /// retruns just the center information
    /** @param centers count of prototypes to use 
        @param steps count of steps to perform 
        @param mmqe mininum mean qauntisation error 
        @param qe quantisation error */
    const VQVectorSet &run(int centers, int steps, float mmqe, float &qe);
    
    /// calculates advanced features like local pca
    const VQClusterInfo &features();

    /// return the centers of all clusters
    const VQVectorSet &centers();
    
    protected:
    VQVectorSet *m_poCenters;       ///!< center data
    VQClusterInfo *m_poClusterInfo; ///!< additinal cluster information
    VQVectorSet *m_poData;          ///!< data
  };
}

#endif