opencv最小二乘法拟合平面

 //Ax+by+cz=D
 void cvFitPlane(const CvMat* points, float* plane){
     // Estimate geometric centroid.
     int nrows = points->rows;
     int ncols = points->cols;
     int type = points->type;
     CvMat* centroid = cvCreateMat(1, ncols, type);
     cvSet(centroid, cvScalar(0));
     for (int c = 0; c
         for (int r = 0; r < nrows; r++)
         {
             centroid->data.fl[c] += points->data.fl[ncols*r + c];
         }
         centroid->data.fl[c] /= nrows;
     }
     // Subtract geometric centroid from each point.
     CvMat* points2 = cvCreateMat(nrows, ncols, type);
     for (int r = 0; r
         for (int c = 0; c
             points2->data.fl[ncols*r + c] = points->data.fl[ncols*r + c] - centroid->data.fl[c];
     // Evaluate SVD of covariance matrix.
     CvMat* A = cvCreateMat(ncols, ncols, type);
     CvMat* W = cvCreateMat(ncols, ncols, type);
     CvMat* V = cvCreateMat(ncols, ncols, type);
     cvGEMM(points2, points, 1, NULL, 0, A, CV_GEMM_A_T);
     cvSVD(A, W, NULL, V, CV_SVD_V_T);
     // Assign plane coefficients by singular vector corresponding to smallest singular value.
     plane[ncols] = 0;
     for (int c = 0; c
         plane[c] = V->data.fl[ncols*(ncols - 1) + c];
         plane[ncols] += plane[c] * centroid->data.fl[c];
     }
     // Release allocated resources.
     cvReleaseMat(¢roid);
     cvReleaseMat(&points2);
     cvReleaseMat(&A);
     cvReleaseMat(&W);
     cvReleaseMat(&V);
 }

调用的方式：

 CvMat*points_mat = cvCreateMat(X_vector.size(), 3, CV_32FC1);//定义用来存储需要拟合点的矩阵
         for (int i=0;i < X_vector.size(); ++i)
         {
             points_mat->data.fl[i*3+0] = X_vector[i];//矩阵的值进行初始化   X的坐标值
             points_mat->data.fl[i * 3 + 1] = Y_vector[i];//  Y的坐标值
             points_mat->data.fl[i * 3 + 2] = Z_vector[i];"font-family: Arial, Helvetica, sans-serif;">//  Z的坐标值

         }
         float plane12[4] = { 0 };//定义用来储存平面参数的数组
         cvFitPlane(points_mat, plane12);//调用方程

我们拟合出来的方程：Ax+By+Cz=D

其中 A=plane12[0],    B=plane12[1],   C=plane12[2],   D=plane12[3],

这是要注意的方程的表示