www.pudn.com > zhangzhengyou.rar > axb.m

clc; 
clear; 
x1=[0   0.5  0.5   
   -0.5 -0.5  0    
   1    1     1  ]; 
x2=[ 63.43   92.46   91.8     
     405.5  407.45  438.65    
     1       1       1          ]; 
Npts = length(x1); 
    A = zeros(3*Npts,9); 
     
    O = [0 0 0]; 
    for n = 1:Npts 
	X = x1(:,n)';%定义  
	x = x2(1,n); y = x2(2,n); w = x2(3,n); 
	A(3*n-2,:) = [  O  -w*X  y*X]; 
	A(3*n-1,:) = [ w*X   O  -x*X]; 
	A(3*n  ,:) = [-y*X  x*X   O ] 
    end 
    [U,D,V] = svd(A); 
    % Ax=b  x=A\b; 
    % Extract homography单应性矩阵 
    H1 = reshape(V(:,9),3,3)'; 
    H=H1/H1(3,3)