evaluatethreshold.m

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%#    mffmsilhouette : Silhouette extraction algorithm
%#    Copyright (C) 2003  Matt Flax, Regina
%#
%#    This program is free software; you can redistribute it and/or modify
%#    it under the terms of the GNU General Public License as published by
%#    the Free Software Foundation; either version 2 of the License, or
%#    (at your option) any later version.
%#
%#    This program is distributed in the hope that it will be useful,
%#    but WITHOUT ANY WARRANTY; without even the implied warranty of
%#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%#    GNU General Public License for more details.
%#
%#    You should have received a copy of the GNU General Public License
%#    along with this program; if not, write to the Free Software
%#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
%#
%#
%#    Matt Flax <[e-mail]>
function thresh=evaluateThreshold(histogram,averageMatrix,frameCnt, globalThreshold)

%# this function evaluates equation 2
n_dash=find((histogram/frameCnt)>globalThreshold);

%# this may be sped up by remoing the for loops and replacing
%# with appropriate code.
[r,c]=size(averageMatrix);
for j=1:r
   for k=1:c
        thresh(j,k)=max(abs(n_dash-averageMatrix(j,k)));
    endfor
endfor
endfunction