code: def _hex2rgb_arr_uint8(hex_c, alpha=None):
      """
      Create 'palette' for PyPNG PNG writer
      """
      return numpy.array(_hex2rgb(hex_c, alpha), dtype=numpy.uint8)
  
file_path: lets-plot/python-package/lets_plot/plot/geom_imshow_.py
imports: import base64
  import io
  from .core import aes
  from .geom import _geom
  from .scale import scale_gradientn
  from .scale import scale_grey
  from .util import as_boolean
  from .util import is_ndarray
label_desc: Use image node_id 2 for calling a global function with example usage: _hex2rgb_arr_uint8(hex_c, alpha) and returns: numpy