code: def test_image_detection():
      rgb = (32, 64, 3)
      gray = (43, 23, 1)
      rgbd = (12, 32, 4)
      invalid_1 = (32, 12)
      invalid_2 = (12, 32, 6)
  
      # TF checks
      for shape in (rgb, gray, rgbd):
          assert is_image(tf.placeholder(tf.uint8, shape=shape))
  
      for shape in (invalid_1, invalid_2):
          assert not is_image(tf.placeholder(tf.uint8, shape=shape))
  
      # Numpy checks
      for shape in (rgb, gray, rgbd):
          assert is_image(np.ones(shape))
  
      for shape in (invalid_1, invalid_2):
          assert not is_image(np.ones(shape))
  
imports: import numpy
  import tensorflow
  from stable_baselines.common.tf_util import function, initialize, single_threaded_session, is_image
label_desc: Use image node_id 3 for calling a global function with example usage: test_image_detection() without return types