contrib/brl/bbas/bsta/bsta_int_histogram_2d.h

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// This is brl/bbas/bsta/bsta_int_histogram_2d.h
#ifndef bsta_int_histogram_2d_h_
#define bsta_int_histogram_2d_h_
//-----------------------------------------------------------------------------
//:
// \file
// \brief 1D and 2D integer Histograms with bucket width = 1
//
//  This simple histogram class is an integer version of gel/vifa/vifa_histogram.h
//    which was a port from Targetjr.  Also borrowed from bsta_histogram.  Only the
//    features needed for integer histograms of images with bucket_width = 1 are included.
//    The class is defined to create a histogram with long int buckets (4 bytes).
//
//  Note that the 2D version is lacking some of the 1D methods because it isn't obvious
//    that they would be of any use for a 2D histogram
//
//  The 2D histogram is a special case useful for isolating similarly colored regions
//    of an image.  Probably not very generally useful to the vxl community.  But here
//    it is anyway
//
//  This is initially placed in bbas/bsta for now.  If others think it useful, it can be
//    moved to a permanent home later.
//
// \author James E. Green
// \date   23 April, 2007
//
// \verbatim
//  Modifications
//   2007/04/23 Initial Version
// \endverbatim
//-----------------------------------------------------------------------------

#include <vcl_vector.h>
#include <vcl_cassert.h>
#include <bsta/bsta_int_histogram_1d.h>

class bsta_int_histogram_2d
{
 private:
  unsigned int nbins_x_;
  unsigned int nbins_y_;
  unsigned int diag_;                               // # buckets in diagonal 1D hist
  vcl_vector<vcl_vector<long int> > counts_;        // the histogram buckets

 public:

  //:default constructor that assumes all data values are positive constructor parameters:
  // \param nbins_x, \param nbins_y      # bins to create in this 2D histogram.
  bsta_int_histogram_2d(const unsigned int nbins_x, const unsigned int nbins_y);

  // destructor
  ~bsta_int_histogram_2d() ;

  // The number of bins in the histogram
  unsigned int nbins_x() const { return nbins_x_;}
  unsigned int nbins_y() const { return nbins_y_;}

  //: get the count in a given bin
  long int get_count(const unsigned int binx, const unsigned int biny)
  { assert(binx < nbins_x_ && biny < nbins_y_); return counts_[biny][binx]; }

  //: set the count in a given bin
  void set_count(const unsigned int binx, const unsigned int biny, const long int count)
  { if (binx<nbins_x_ && biny<nbins_y_) counts_[biny][binx] = count; }

  //: Total area under the histogram = total counts in histogram
  unsigned long int get_area();

  // get highest value in histogram; returns max value; index of max is available in imax
  unsigned long int get_max_val(unsigned int &imax_x, unsigned int &imax_y);

  //: Smooth the 2D histogram with a Parzen window of sigma
  void parzen(const float sigma);

  //: Form a "profile" histogram along the diagonal with max value normal to diagonal in buckets
  void profile_histogram( bsta_int_histogram_1d &phist,
                          bsta_int_histogram_1d &phist_x,
                          bsta_int_histogram_1d &phist_y );

  //: Find where peak drops to X% along normal on either front or rear edge of diagonal slope.
  //  Here the "front" is the top edge, "rear" is the bottom edge
  bool find_edge( unsigned int peak_y, unsigned int peak_x,
                  float newslope, float edgepct,
                  unsigned int &edge_x, unsigned int &edge_y,
                  bool front);
};

#endif // bsta_int_histogram_2d_h_