code: def prelu(f_in, channelwise_params):
      pos = tf.nn.relu(f_in)
      neg = channelwise_params * (f_in - tf.abs(f_in)) * 0.5
      return pos + neg
  
file_path: NiftyNet/niftynet/layer/activation.py
imports: from __future__ import absolute_import, print_function
  import tensorflow
  from niftynet.layer.base_layer import TrainableLayer
  from niftynet.utilities.util_common import look_up_operations
label_desc: Use image node_id 1 for calling a global function with example usage: prelu(f_in, channelwise_params) and returns: unknown