clear all;

% Setup data

image_list = mGetImageFileList;
	   
zero_bin = zeros( 2^8, 2^8 );	   

image_total = size( image_list, 1 );

Hu0_total = 0;
%image_size_total = 0;


for image_count = 1:2:image_total
  image_l_name = deblank( image_list( image_count,: ) )
  image_l = pgmRead( sprintf( '../images/%s', image_l_name ) );
  image_r_name = deblank( image_list( image_count+1,: ) )
  image_r = pgmRead( sprintf( '../images/%s', image_r_name ) );
  
  [ row_total, col_total ] = size( image_l );
  image_size = row_total*col_total;
  
  bin = zero_bin;
  for row = 1:row_total
    for col = 1:col_total
      bin_row_index = image_l( row, col )+1;
      bin_col_index = image_r( row, col )+1;
      % zero is not a valid index -> add 1
      bin( bin_row_index, bin_col_index ) = bin( bin_row_index, bin_col_index ) + 1;
    end
  end
  
  % Normalize to find pdf
  PDF = bin / sum( sum( bin ) );
  
  if image_count == 2  % display joint histogram for first image
    mPlotJointPDF( [ image_l_name ', ' image_r_name ], 'Left image pixel', [ 0:255 ], 'Right image pixel', [ 0:255 ], 'MPD', PDF );
  end


  % x*log(x) = log(x^x)
  PlogP = log( PDF.^PDF)/log(2);
  
  Hu0 = -sum( sum( PlogP ) )
  
  Normalized_Hu0 = Hu0/2
  
  Hu0_total = Hu0_total + Hu0;%*image_size;
%  image_size_total = image_size_total + image_size;

end


% Overall statistics:

fprintf( 2, 'Combined images:\n' )

% Normalize to find pdf
Average_Hu0 = Hu0_total/(image_total/2) %image_size_total

Normalized_Average_Hu0 = Average_Hu0/2