kktv_datagame_1711_instance_norm.py

def instance_norm(flow):
    """
    arXiv:1607.08022v2
    """
    with tf.variable_scope('inst_norm'):
        depth = flow.get_shape()[3]
        scale = tf.get_variable(
            'scale',
            [depth],
            initializer=tf.random_normal_initializer(1.0, 0.02))
        shift = tf.get_variable(
            'shift',
            [depth],
            initializer=tf.constant_initializer(0.0))

        mean, variance = tf.nn.moments(flow, axes=[1, 2], keep_dims=True)

        flow = (flow - mean) / tf.sqrt(variance + 1e-5)

        return scale * flow + shift