code: def updateLUT():
      global LUT, ui
      dtype = ui.dtypeCombo.currentText()
      if dtype == "uint8":
          n = 256
      else:
          n = 4096
      LUT = ui.gradient.getLookupTable(
          n, alpha=ui.alphaCheck.isChecked()
      )
      if _has_cupy and xp == cp:
          LUT = cp.asarray(LUT)
  
file_path: pyqtgraph/pyqtgraph/examples/VideoSpeedTest.py
imports: import argparse
  import itertools
  import sys
  import numpy
  from utils import FrameCounter
  import pyqtgraph
  from pyqtgraph.Qt import QtCore, QtGui, QtWidgets
  import VideoTemplate_generic
label_desc: Use image node_id 1 for calling a global function with example usage: updateLUT() without return types