% SAMPLE2D - Sample a 2D area using Gaussian Sampling 
%
% Usage:
%
% function s = Sample2D(im,x0,y0,m,sig)
%
% Arguments:
%
% im    = The image.
% x0,y0 = position in im.
% m     = mask size.
% sig   = sigma of the Gaussian funcion.
%
% Returns:
%
% s     = sample
%
% Copyright (c) 2012-2013 Anders Hast
% Uppsala University
% http://www.cb.uu.se/~aht
% 
% 
% Permission is hereby granted, free of charge, to any person obtaining a copy
% of this software and associated documentation files (the "Software"), to deal
% in the Software without restriction, subject to the following conditions:
% 
% The above copyright notice and this permission notice shall be included in 
% all copies or substantial portions of the Software.
%
% The Software is provided "as is", without warranty of any kind.
%
function s = Sample2D(im,x0,y0,m,sig)
    x=floor(x0);
    y=floor(y0);
    m=floor(m/2);
    gs=0;
    s=0;

    for i=-m:m
        for j=-m:m
            g = Gauss2D(x+i,y+j,x0,y0,sig);
            gs=gs+g;
            s=s+g*im(x+i,y+j);
         end
    end
    s=s/gs;
end