%   BWKEEP Keeping the largest regions in image 
%
%   BW = BWKEEP(BW,VAL,CONN) keeps the VAL largest regions in BW using the
%   connectivity in CONN
%
% 
%   =======================================================================================
%   Copyright (C) 2013  Erlend Hodneland
%   Email: erlend.hodneland@biomed.uib.no 
% 
%   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 3 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, see <http://www.gnu.org/licenses/>.
%   =======================================================================================
%
function [bw] = bwkeep(bw,val,conn)


[dim,faser] = bwsize(bw,conn);
bw = zeros(size(bw));
[sorted,ind] = sort(dim,'descend');

numreg = length(dim);
% val = unique(faser(faser > 0)));
for i = 1 : val
    if i > numreg
        break;
    end;
    valhere = ind(i);
    reghere = faser == valhere;

    bw(reghere == 1) = 1; 
end;