這裏是Matlab代碼..它可能會幫助
function [Q,a]=fit_ellipse_fitzgibbon(data)
% function [Q,a]=fit_ellipse_fitzgibbon(data)
%
% Ellipse specific fit, according to:
%
% Direct Least Square Fitting of Ellipses,
% A. Fitzgibbon, M. Pilu and R. Fisher. PAMI 1996
%
%
% See Also:
% FIT_ELLIPSE_LS
% FIT_ELLIPSE_HALIR
[m,n] = size(data);
assert((m==2||m==3)&&n>5);
x = data(1,:)';
y = data(2,:)';
D = [x.^2 x.*y y.^2 x y ones(size(x))]; % design matrix
S = D'*D; % scatter matrix
C(6,6)=0; C(1,3)=-2; C(2,2)=1; C(3,1)=-2; % constraints matrix
% solve the generalized eigensystem
[V,D] = eig(S, C);
% find the only negative eigenvalue
[n_r, n_c] = find(D<0 & ~isinf(D));
if isempty(n_c),
warning('Error getting the ellipse parameters, will do LS');
[Q,a] = fit_ellipse_ls(data); %
return;
end
% the parameters
a = V(:, n_c);
[A B C D E F] = deal(a(1),a(2),a(3),a(4),a(5),a(6)); % deal is slow!
Q = [A B/2 D/2; B/2 C E/2; D/2 E/2 F];
end % fit_ellipse_fitzgibbon
Fitzibbon解決方案有一些數值穩定性雖然。請參閱Halir的工作以獲得解決方案。
它基本上是最小二乘法解決方案,但專門設計的,使得它將產生一個有效的橢圓,不僅僅是任何圓錐曲線。