code: def rgb_to_greyscale(image):
      if image.shape[-1] == 4:
          output = skimage.color.rgba2rgb(image)
          return skimage.color.rgb2gray(output)
      else:
          return skimage.color.rgb2gray(image)
  
imports: import numpy
  import skimage.color
  import skimage.morphology
  import centrosome
  import centrosome.threshold
  import scipy
  import matplotlib
label_desc: Use image node_id 1 for calling a global function with example usage: rgb_to_greyscale(image) and returns: skimage, skimage