code: def decfa(img_orig, scale=False):
      """
      Create a nifti-compliant directional-encoded color FA image.
  
      Parameters
      ----------
      img_orig : Nifti1Image class instance.
          Contains encoding of the DEC FA image with a 4D volume of data, where
          the elements on the last dimension represent R, G and B components.
  
      scale: bool.
          Whether to scale the incoming data from the 0-1 to the 0-255 range
          expected in the output.
  
      Returns
      -------
      img : Nifti1Image class instance with dtype set to store tuples of
          uint8 in (R, G, B) order.
  
  
      Notes
      -----
      For a description of this format, see:
  
      https://nifti.nimh.nih.gov/nifti-1/documentation/nifti1fields/nifti1fields_pages/datatype.html
      """
  
      dest_dtype = np.dtype(
          [("R", "uint8"), ("G", "uint8"), ("B", "uint8")]
      )
      out_data = np.zeros(img_orig.shape[:3], dtype=dest_dtype)
  
      data_orig = np.asanyarray(img_orig.dataobj)
  
      if scale:
          data_orig = (data_orig * 255).astype("uint8")
  
      for ii in np.ndindex(img_orig.shape[:3]):
          val = data_orig[ii]
          out_data[ii] = (val[0], val[1], val[2])
  
      new_hdr = img_orig.header
      new_hdr["dim"][4] = 1
      new_hdr.set_intent(1001, name="Color FA")
      new_hdr.set_data_dtype(dest_dtype)
  
      return Nifti1Image(
          out_data, affine=img_orig.affine, header=new_hdr
      )
  
imports: import logging
  import numbers
  import os
  from dipy.utils.optpkg import optional_package
  import dipy
  import nibabel
  from nibabel.streamlines import detect_format
  from nibabel import Nifti1Image
  import numpy
  from trx import trx_file_memmap
label_desc: Use image node_id 3 for calling a global function with example usage: decfa(img_orig, scale) and returns: Nifti1Image