1 %% Copyright (c) 2011, INRA
2 %% 2009-2011, David Legland <david.legland@grignon.inra.fr>
3 %% 2011 Adapted to Octave by Juan Pablo Carbajal <carbajal@ifi.uzh.ch>
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35 %% @deftypefn {Function File} {@var{T} = } fitAffineTransform2d (@var{pts1}, @var{pts2})
36 %% Fit an affine transform using two point sets.
42 %% pts = rand(N, 2)*10;
43 %% trans = createRotation(3, 4, pi/4);
44 %% pts2 = transformPoint(pts, trans);
45 %% pts3 = pts2 + randn(N, 2)*2;
46 %% fitted = fitAffineTransform2d(pts, pts2)
49 %% @seealso{transforms2d}
52 function trans = fitAffineTransform2d(pts1, pts2)
57 % main matrix of the problem
59 pts1(:,1) pts1(:,2) ones(N,1) zeros(N, 3) ; ...
60 zeros(N, 3) pts1(:,1) pts1(:,2) ones(N,1) ];
62 % conditions initialisations
63 B = [pts2(:,1) ; pts2(:,2)];
65 % compute coefficients using least square
69 trans = [coefs(1:3)' ; coefs(4:6)'; 0 0 1];