55 lines
1.8 KiB
Python
55 lines
1.8 KiB
Python
# Licensed to the Apache Software Foundation (ASF) under one
|
|
# or more contributor license agreements. See the NOTICE file
|
|
# distributed with this work for additional information
|
|
# regarding copyright ownership. The ASF licenses this file
|
|
# to you under the Apache License, Version 2.0 (the
|
|
# "License"); you may not use this file except in compliance
|
|
# with the License. You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing,
|
|
# software distributed under the License is distributed on an
|
|
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
|
|
# KIND, either express or implied. See the License for the
|
|
# specific language governing permissions and limitations
|
|
# under the License.
|
|
# pylint: disable=invalid-name, line-too-long, unused-variable, too-many-locals
|
|
"""Instance normalization in python"""
|
|
|
|
import numpy as np
|
|
|
|
|
|
def instance_norm_python(data, gamma, beta, axis, epsilon=1e-5):
|
|
"""Instance normalization operator in Python.
|
|
|
|
Parameters
|
|
----------
|
|
data : numpy.ndarray
|
|
N-D with shape (d_0, d_1, ..., d_{N-1})
|
|
|
|
gamma: numpy.ndarray
|
|
K-D with shape (r_0, r_1, ..., r_{K-1}) where K == len(axis) and d_{axis_k} == r_k
|
|
|
|
beta: numpy.ndarray
|
|
Optional, K-D with shape (r_0, r_1, ..., r_{K-1}) where K == len(axis) and d_{axis_k} == r_k
|
|
|
|
axis : int or tuple of ints
|
|
Axis over the normalization applied
|
|
|
|
epsilon : float
|
|
The epsilon value to avoid division by zero.
|
|
|
|
Returns
|
|
-------
|
|
result : np.ndarray
|
|
N-D with shape (d_0, d_1, ..., d_{N-1})
|
|
"""
|
|
mean = np.mean(data, axis, keepdims=True)
|
|
var = np.var(data, axis, keepdims=True)
|
|
result = (data - mean) / np.sqrt(var + epsilon)
|
|
result *= gamma
|
|
if beta is not None:
|
|
result += beta
|
|
return result
|