code: def pinhole_matrix(pinholes: Tensor, eps: float = 1e-6) -> Tensor:
      r"""Function that returns the pinhole matrix from a pinhole model.
  
      .. note::
          This method is going to be deprecated in version 0.2 in favour of
          :attr:`kornia.PinholeCamera.camera_matrix`.
  
      Args:
          pinholes: tensor of pinhole models.
  
      Returns:
          tensor of pinhole matrices.
  
      Shape:
          - Input: :math:`(N, 12)`
          - Output: :math:`(N, 4, 4)`
  
      Example:
          >>> rng = torch.manual_seed(0)
          >>> pinhole = torch.rand(1, 12)    # Nx12
          >>> pinhole_matrix(pinhole)  # Nx4x4
          tensor([[[4.9626e-01, 1.0000e-06, 8.8477e-02, 1.0000e-06],
                   [1.0000e-06, 7.6822e-01, 1.3203e-01, 1.0000e-06],
                   [1.0000e-06, 1.0000e-06, 1.0000e+00, 1.0000e-06],
                   [1.0000e-06, 1.0000e-06, 1.0000e-06, 1.0000e+00]]])
      """
      # warnings.warn("pinhole_matrix will be deprecated in version 0.2, "
      #              "use PinholeCamera.camera_matrix instead",
      #              PendingDeprecationWarning)
      if not (len(pinholes.shape) == 2 and pinholes.shape[1] == 12):
          raise AssertionError(pinholes.shape)
      # unpack pinhole values
      fx, fy, cx, cy = torch.chunk(pinholes[..., :4], 4, dim=1)  # Nx1
      # create output container
      k = eye(4, device=pinholes.device, dtype=pinholes.dtype) + eps
      k = k.view(1, 4, 4).repeat(pinholes.shape[0], 1, 1)  # Nx4x4
      # fill output with pinhole values
      k[..., 0, 0:1] = fx
      k[..., 0, 2:3] = cx
      k[..., 1, 1:2] = fy
      k[..., 1, 2:3] = cy
      return k
  
imports: from typing import Iterable, List, Union
  import torch
  from kornia.core import Device, Tensor, eye, stack, zeros
  from kornia.core.check import KORNIA_CHECK_SAME_DEVICE
  from kornia.geometry.conversions import convert_points_from_homogeneous, convert_points_to_homogeneous
  from kornia.geometry.linalg import inverse_transformation, transform_points
  from kornia.utils.helpers import _torch_inverse_cast
label_desc: Use image node_id 1 for calling a global function with example usage: pinhole_matrix(pinholes, eps) and returns: k