code: def cam2pixel(
      cam_coords_src: Tensor, dst_proj_src: Tensor, eps: float = 1e-12
  ) -> Tensor:
      r"""Transform coordinates in the camera frame to the pixel frame.
  
      Args:
          cam_coords: (x, y, z) coordinates defined in the first camera coordinates system. Shape must be BxHxWx3.
          dst_proj_src: the projection matrix between the
            reference and the non reference camera frame. Shape must be Bx4x4.
          eps: small value to avoid division by zero error.
  
      Returns:
          tensor of shape BxHxWx2 with (u, v) pixel coordinates.
      """
      if (
          not len(cam_coords_src.shape) == 4
          and cam_coords_src.shape[3] == 3
      ):
          raise ValueError(
              f"Input cam_coords_src has to be in the shape of BxHxWx3. Got {cam_coords_src.shape}"
          )
      if not len(dst_proj_src.shape) == 3 and dst_proj_src.shape[
          -2:
      ] == (4, 4):
          raise ValueError(
              f"Input dst_proj_src has to be in the shape of Bx4x4. Got {dst_proj_src.shape}"
          )
      # apply projection matrix to points
      point_coords: Tensor = transform_points(
          dst_proj_src[:, None], cam_coords_src
      )
      x_coord: Tensor = point_coords[..., 0]
      y_coord: Tensor = point_coords[..., 1]
      z_coord: Tensor = point_coords[..., 2]
  
      # compute pixel coordinates
      u_coord: Tensor = x_coord / (z_coord + eps)
      v_coord: Tensor = y_coord / (z_coord + eps)
  
      # stack and return the coordinates, that's the actual flow
      pixel_coords_dst: Tensor = stack([u_coord, v_coord], dim=-1)
      return pixel_coords_dst
  
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 7 for calling a global function with example usage: cam2pixel(cam_coords_src, dst_proj_src, eps) and returns: pixel_coords_dst