function [ y ] = probDensity( x , pobj, pbkg)
% Function to compute the log likelihood ratio for observing color I(x) at a point x  

if x~=0 && pobj(x)~=0 && pbkg(x)/(pobj(x))~=0
    y = (log(pbkg(x)/(pobj(x))));
else 
    y=0;
end
end

