% LOGPOLARGAUSS - Log Polar Transform with Gaussian Sampling 
%
% Usage:
%
% function lp = logpolarGauss(im,x0,y0,r,s,m,sig)
%
% Arguments:
%
% im    = The image.
% x0,y0 = position in im.
% r     = Radius in pixels.
% s     = size of the logolar image.
% m     = mask size.
% sig   = sigma of the Gaussian funcion.
%
% Returns:
%
% lp    = logpolar image.
%
% 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 lp = logpolarGauss(im,x0,y0,r,s,m,sig)   
    lp=zeros(s,s);
    k1=log(r+1)/(s-1);
    k2=s/(2*pi);
    
    for i=1:s
        for j=1:s
            t=j/k2;
            e=exp((i-1)*k1)-1;
            x=e*cos(t)+x0;
            y=e*sin(t)+y0;

            lp(i,j) = Sample2D(im,x,y,m,sig);
        end
    end
end