Merge branch 'main' of https://github.com/didibib/multimedia-retrieval

src/mmr/src/normalization.cpp

@@ -30,7 +30,47 @@ void Norma::translate(SurfaceMesh& mesh)
     }
 }
 
-void Norma::pca(SurfaceMesh& mesh) {}
+void Norma::pca(SurfaceMesh& mesh) {
+    unsigned int n_vertices = mesh.n_vertices();
+    MatrixXf input(3, n_vertices);
+
+    unsigned int i = 0;
+    for (auto v : mesh.vertices())
+    {
+        input.row(i)[0] = mesh.position(v)[0];
+        input.row(i)[1] = mesh.position(v)[1];
+        input.row(i++)[2] = mesh.position(v)[2];
+    }
+
+    VectorXf mean = input.rowwise().mean();
+    MatrixXf centered = input.colwise() - mean;
+
+    MatrixXf cov = centered * centered.adjoint();
+    cov = cov.array() / (input.rows() - 1);
+    SelfAdjointEigenSolver<MatrixXf> eig(cov);
+
+    VectorXf::Index maxv, minv;
+    float val = eig.eigenvalues().maxCoeff(&maxv);
+    eig.eigenvalues().minCoeff(&minv);
+
+    Matrix3f transfer;
+    transfer.col(0) = eig.eigenvectors().col(maxv);
+    transfer.col(2) = eig.eigenvectors().col(minv);
+    transfer.col(1) = transfer.col(0).cross(transfer.col(2));
+
+    /*Vector3f pos_temp;
+    for (auto v : mesh.vertices())
+    {
+        pos_temp[0] = mesh.position(v)[0];
+        pos_temp[1] = mesh.position(v)[1];
+        pos_temp[2] = mesh.position(v)[2];
+        pos_temp *= transfer;
+        pos_temp /= val;
+        mesh.position(v)[0] = pos_temp[0];
+        mesh.position(v)[1] = pos_temp[1];
+        mesh.position(v)[2] = pos_temp[2];
+    }*/
+}
 
 void Norma::flip(SurfaceMesh& mesh) {}