code: def pack_unit(value):
      """Packs float values between [0,1] into 4 unsigned int8
  
      Returns
      -------
      pack: array
          packed interpolation kernel
      """
      pack = np.zeros(value.shape + (4,), dtype=np.ubyte)
      for i in range(4):
          value, pack[..., i] = np.modf(value * 256.0)
      return pack
  
file_path: vispy/vispy/io/datasets.py
imports: import numpy
  from os import path
  from ..util import load_data_file
label_desc: Use image node_id 3 for calling a global function with example usage: pack_unit(value) and returns: pack