 b/utils/triangulation.py
+# Given target 2D coordinates and camera matrices from two camera views,
+# triangulate the target 3D coordinates
+import numpy as np
+import cv2 as cv
+def to_homog(points):
+    """
+    Function: convert points from Euclidean coordinates to homogeneous coordinates
+    points: 3xn numpy array containing Euclidean coordinates
+    Return: 4xn numpy array containing homogeneous coordinates
+    """
+    m, n = points.shape
+    points_homog = np.concatenate([points, np.ones([1, n])], axis=0)
+    return points_homog
+def from_homog(points_homog):
+    """
+    Function: convert points from homogeneous coordinates to Eulidean coordinates
+    points_homog: 4xn numpy array containing homogeneous coordinates
+    Return: 3xn numpy array containing Euclidean coordinates
+    """
+    m, n = points_homog.shape
+    points = points_homog[:m-1] / points_homog[m-1]
+    return points
+def reconstruct(pts1, pts2, int1, int2, ext1, ext2):
+    """
+   Function: reconstruct 3D points with given correspondence
+   int1, int2: intrinsic matrices of camera 1 and camera 2
+   ext1, ext2: extrinsic matrices of camera 1 and camera 2
+   Return: 3xn numpy arrays containing the Euclidean coordinates of reconstructed 3D points
+   """
+    I_0 = np.hstack((np.eye(3), np.zeros((3, 1))))
+    proj1 = int1 @ I_0 @ ext1
+    proj2 = int2 @ I_0 @ ext2
+    homo_coor = cv.triangulatePoints(proj1, proj2, pts1, pts2)
+    recon = from_homog(homo_coor)
+    return recon