code: def test_gibbs_2d():
      # Correction of gibbs ringing have to be closer to gt than denoised image
      diff_raw = np.mean(abs(image_gibbs - image_gt))
      diff_cor = np.mean(abs(image_cor - image_gt))
      assert_(diff_raw > diff_cor)
  
      # Test if gibbs_removal works for 2D data
      image_cor2 = gibbs_removal(image_gibbs, inplace=False)
      assert_array_almost_equal(image_cor2, image_cor)
  
file_path: dipy/dipy/denoise/tests/test_gibbs.py
imports: import numpy
  from dipy.denoise.gibbs import _gibbs_removal_1d, _gibbs_removal_2d, gibbs_removal, _image_tv
  from numpy.testing import assert_, assert_array_almost_equal, assert_raises
label_desc: Use image node_id 4 for calling a global function with example usage: test_gibbs_2d() without return types