direction=finddirection(first,second);

% the function finddirection takes two pixel coordinates as arguments
% returns the direction of the second pixel with respect to first
% considering the first pixel as the centre pixel.The numbering is in
% clockwise direction. The pixel below central pixel is numbered as 1 and
% the rest are numbered in clockwise direction.
function direction=finddirection(first,second);
direction=0;
position = second-first;
if     position==[1,0]
    direction=1;
elseif position==[1,-1]
    direction=2;
elseif position==[0,-1]
    direction=3;
elseif position==[-1,-1]
    direction=4;
elseif position==[-1,0]
    direction=5;
elseif position==[-1,1]
    direction=6;
elseif position==[0,1]
    direction=7;
elseif position==[1,1]
    direction=8;
end