function F=doflatten(img, dg, ind)
%DOFLATTEN Flatten the image

%
% Copyright (c) 1995 by Claudio Rivetti and Mark Young
% claudio@alice.uoregon.edu,    mark@alice.uoregon.edu
%

global Handlefig

f=watchon;
im=zeros(size(img));
im(ind)=im(ind)*NaN;
rows=size(img,1);
cols=size(img,2);

F=zeros(rows, cols);
x=1:cols;

for i=1:rows
    y=im(i,x);
    indx=find(~isnan(y));
    xx=x(indx);
    c=polyfit(xx,img(i,indx), dg);
    F(i,x)=img(i,x) - polyval(c,x);
    progressbar(i/rows, 'Flattening image');
end

watchoff(f);
return;