gethifrom7params.m

这是我用Delphi和Matlab写的一个程序

function [H0, H1] = GetHiFrom7Params(Vector);
%  GETHIFROM7PARAMS  Return the projective transformation matrices(prewarping transforms) 
%  from the 7 parameters: [f(x1), f(x2), ..., f(xn)]，通过7个参数计算投影变换矩阵
%  Vector: 七个参数[alfa, a, b, e0x, e0y, e1x, e1y]的初始值组成的向量
%  H0, H1: the projective transformation matrices
%
%  Ran Liu: [e-mail]
%  College of Computer Science, Chongqing University
%  Panovasic Technology Co.,Ltd

alfa = Vector(1);
a = Vector(2); 
b = Vector(3);
e0x = Vector(4);
e0y = Vector(5);
e1x = Vector(6);
e1y = Vector(7);

d0x = e0y / sqrt(e0x^2 + e0y^2);
d0y = -e0x / sqrt(e0x^2 + e0y^2);

d1x = cos(alfa);
d1y = sin(alfa);

theta0 = atan(1 / (d0y * e0x - d0x * e0y));  %  计算theta0: I0的深度旋转角度
R0Planes = MatAlignImgPlanes(theta0, d0x, d0y);  %  计算图像平面I0旋转变换矩阵
e0New = R0Planes * [e0x; e0y; 1];  %  计算变换后的e0的坐标
beta0 = -atan(e0New(2) / e0New(1));  %  计算参数beta0: I0中的极线旋转角度
R0Lines = MatAlignScanlines(beta0); %  计算I0中的极线旋转变换矩阵

theta1 = atan(1 / (d1y * e1x - d1x * e1y));  %  计算theta1: I1的深度旋转角度
R1Planes = MatAlignImgPlanes(theta1, d1x, d1y);  %  计算图像平面I1旋转变换矩阵
e1New = R1Planes * [e1x; e1y; 1];  %  计算变换后的e1的坐标
beta1 = -atan(e1New(2) / e1New(1));  %  计算参数beta1: I1中的极线旋转角度
R1Lines = MatAlignScanlines(beta1); %  计算I1中的极线旋转变换矩阵。
                                    %  由于在函数InitialParams已经保证a >
                                    %  0，因此这里代beta1
T = [1   0   0
     0   a   b
     0   0   1 ];

%  计算Hi
H0 = R0Lines * R0Planes;
H1 = T * R1Lines * R1Planes;