code: def assert_images_match(image1, image2, threshold=0.1):
      """Assert that images are matching."""
      img1 = np.asarray(Image.open(image1))
      img2 = np.asarray(Image.open(image2))
      rms = fft_proj_rms(img1, img2)
      assert (
          rms <= threshold
      ), "Images {0} and {1} don't match: {2}".format(
          image1, image2, rms
      )
  
file_path: satpy/satpy/tests/features/steps/steps-real-load-process-write.py
imports: import fnmatch
  import os
  from tempfile import NamedTemporaryFile
  import numpy
  from behave import given, then, when
  from PIL import Image
label_desc: Use image node_id 2 for calling a global function with example usage: assert_images_match(image1, image2, threshold) without return types