第一节,ICP算法
P
2
=
P
1
+
t
P_2 = P_1+t
P2=P1+t
W
=
q
2
∗
q
1
T
W = q2*q1^{T}
W=q2∗q1T
/**
* 手撕ICP算法
* points2 = R* points1+ t
* W = q2*q1,transpose()
* 估计值为R1,t1
* wpf
* */
#include <iostream>
#include <vector>
#include <eigen3/Eigen/Core>
#include <eigen3/Eigen/Dense>
using namespace Eigen;
using namespace std;
int main() {
//创建一组三维对应点,创建一个旋转矩阵R,一个平移t,求出对应的一组三维点
const vector<Vector3d> Points1{{2,3,5},{6,3,2},{9,4,2}};
vector<Vector3d> Points2;
AngleAxisd rotation_vector(M_PI_4,Vector3d(0,0,1));
cout.precision(3);
Matrix3d R = rotation_vector.toRotationMatrix();
cout<<R<<endl;
Vector3d t(10,15,84);
cout<<t<<endl;
for(int i = 0;i<3;i++){
Points2.emplace_back(R*Points1[i]+t);
}
//去中心化,求和,每个数据减去对应的和,创建矩阵W
Vector3d p1(0,0,0);
Vector3d p2(0,0,0);
for (int i = 0; i < 3; ++i) {
p1 += Points1[i];
p2 += Points2[i];
}
p1 = p1/3;
p2 = p2/3;
vector<Vector3d> q1(3);
vector<Vector3d> q2(3);
for (int i = 0; i < 3; ++i) {
q1[i] = Points1[i]-p1;
q2[i] = Points2[i]-p2;
}
Matrix3d W = Matrix3d::Zero();
for (int i = 0; i < 3; ++i) {
W+= Vector3d(q2[i].x(),q2[i].y(),q2[i].z())*Vector3d(q1[i].x(),q1[i].y(),q1[i].z()).transpose();
}
//SVD分解
JacobiSVD<Matrix3d> svd(W,ComputeFullU|Eigen::ComputeFullV);
Matrix3d U = svd.matrixU();
Matrix3d V = svd.matrixV();
Matrix3d R1 = U*(V.transpose());
if(R1.determinant()<0) R1 = -R1;
cout<<R1<<endl;
Vector3d t1 =Vector3d(p2.x(),p2.y(),p2.z())-R1*Vector3d(p1.x(),p1.y(),p1.z());
cout<<t1.x()<<" "<<t1.y()<<" "<<t1.z()<<endl;
//利用这个方法求解R
//求解t
//输出最后的结果
std::cout << "Hello, World!" << std::endl;
return 0;
}
代码运行结果
/home/wpf/Test/study_cpp/ICP/cmake-build-debug/ICP
0.707 -0.707 0
0.707 0.707 0
0 0 1 10 15 84
0.707 -0.707 1.11e-16
0.707 0.707 -3.33e-16
-1.67e-16 2.78e-16 1
10 15 84
Hello, World!Process finished with exit code 0
代码分析:
由于这里的点仅仅设置3个,所以计算量不大,在实际工程中匹配点的数目也是100左右,运算不会太慢
注意SVD分解的使用