def METHOD_NAME(self):
    int_mat = np.eye(3)
    int_mat[0, 0] = self.focal_x
    int_mat[1, 1] = self.focal_y
    int_mat[0, 1] = self.skew
    int_mat[0, 2] = self.principal_x
    int_mat[1, 2] = self.principal_y
    return int_mat