code: def warp_img(
      fname, target_proj, source_proj=None, target_res=(400, 200)
  ):
      """
      Regrid the image file from the source projection to the target projection.
  
      Parameters
      ----------
      fname
          Image filename to be loaded and warped.
      target_proj
          The target :class:`~cartopy.crs.Projection` instance for the image.
      source_proj: optional
          The source :class:`~cartopy.crs.Projection` instance of the image.
          Defaults to a :class:`~cartopy.crs.PlateCarree` projection.
      target_res: optional
          The (nx, ny) resolution of the target projection. Where nx defaults to
          400 sample points, and ny defaults to 200 sample points.
  
      """
  
      if source_proj is None:
          source_proj = ccrs.PlateCarree()
  
      raise NotImplementedError("Not yet implemented.")
  
imports: import numpy
  import cartopy.crs
label_desc: Use image node_id 2 for calling a global function with example usage: warp_img(fname, target_proj, source_proj, target_res) without return types