imageforces.m

Tracking a moving object through several frames, provided changes from frame to frame are on the ord

function out = imageForces( pnt,...
                            radius_x,...
                            radius_y,...
                            image,...
                            image_gradient )
%
% index_x -\ define the neighborhood
% index_y -/ of the point (pnt) where to estimate image forces
% 

igSize = size(image_gradient);

% Should be a procedure, but I am too lazy
%
h_pnt = pnt + [-radius_x 0];
save_h_pnt = h_pnt;
h_pnt(1) = clipValue(h_pnt(1), 1, igSize(2));
left = (h_pnt(1) - save_h_pnt(1)) + (-radius_x);

h_pnt = pnt + [radius_x 0];
save_h_pnt = h_pnt;
h_pnt(1) = clipValue(h_pnt(1), 1, igSize(2));
right = (h_pnt(1) - save_h_pnt(1)) + radius_x;

h_pnt = pnt + [0 -radius_y];
save_h_pnt = h_pnt;
h_pnt(2) = clipValue(h_pnt(2), 1, igSize(1));
top = (h_pnt(2) - save_h_pnt(2)) + (-radius_y);

h_pnt = pnt + [0 radius_y];
save_h_pnt = h_pnt;
h_pnt(2) = clipValue(h_pnt(2), 1, igSize(1));
bottom = (h_pnt(2) - save_h_pnt(2)) + radius_y;
%
%


pnt_left   = pnt(1) + left;
pnt_right  = pnt(1) + right;
pnt_top    = pnt(2) + top;
pnt_bottom = pnt(2) + bottom;

%igArea = image_gradient(pnt_top:pnt_bottom, pnt_left:pnt_right);
%out = sum(sum(igArea));

out = sum( image_gradient(pnt(2), pnt_left:pnt_right) );
out = out + sum( image_gradient(pnt_top:pnt_bottom, pnt(1)) );
out = -255*out;
end