tensorflow_privacy/research/pate_2017/deep_cnn.py
2020-02-25 14:11:47 -08:00

603 lines
21 KiB
Python

# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
#
# Licensed 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.
# ==============================================================================
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from datetime import datetime
import math
import numpy as np
from six.moves import xrange
import tensorflow.compat.v1 as tf
import time
import utils
FLAGS = tf.app.flags.FLAGS
# Basic model parameters.
tf.app.flags.DEFINE_integer('dropout_seed', 123, """seed for dropout.""")
tf.app.flags.DEFINE_integer('batch_size', 128, """Nb of images in a batch.""")
tf.app.flags.DEFINE_integer('epochs_per_decay', 350, """Nb epochs per decay""")
tf.app.flags.DEFINE_integer('learning_rate', 5, """100 * learning rate""")
tf.app.flags.DEFINE_boolean('log_device_placement', False, """see TF doc""")
# Constants describing the training process.
MOVING_AVERAGE_DECAY = 0.9999 # The decay to use for the moving average.
LEARNING_RATE_DECAY_FACTOR = 0.1 # Learning rate decay factor.
def _variable_on_cpu(name, shape, initializer):
"""Helper to create a Variable stored on CPU memory.
Args:
name: name of the variable
shape: list of ints
initializer: initializer for Variable
Returns:
Variable Tensor
"""
with tf.device('/cpu:0'):
var = tf.get_variable(name, shape, initializer=initializer)
return var
def _variable_with_weight_decay(name, shape, stddev, wd):
"""Helper to create an initialized Variable with weight decay.
Note that the Variable is initialized with a truncated normal distribution.
A weight decay is added only if one is specified.
Args:
name: name of the variable
shape: list of ints
stddev: standard deviation of a truncated Gaussian
wd: add L2Loss weight decay multiplied by this float. If None, weight
decay is not added for this Variable.
Returns:
Variable Tensor
"""
var = _variable_on_cpu(name, shape,
tf.truncated_normal_initializer(stddev=stddev))
if wd is not None:
weight_decay = tf.multiply(tf.nn.l2_loss(var), wd, name='weight_loss')
tf.add_to_collection('losses', weight_decay)
return var
def inference(images, dropout=False):
"""Build the CNN model.
Args:
images: Images returned from distorted_inputs() or inputs().
dropout: Boolean controlling whether to use dropout or not
Returns:
Logits
"""
if FLAGS.dataset == 'mnist':
first_conv_shape = [5, 5, 1, 64]
else:
first_conv_shape = [5, 5, 3, 64]
# conv1
with tf.variable_scope('conv1') as scope:
kernel = _variable_with_weight_decay('weights',
shape=first_conv_shape,
stddev=1e-4,
wd=0.0)
conv = tf.nn.conv2d(images, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [64], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv1 = tf.nn.relu(bias, name=scope.name)
if dropout:
conv1 = tf.nn.dropout(conv1, 0.3, seed=FLAGS.dropout_seed)
# pool1
pool1 = tf.nn.max_pool(conv1,
ksize=[1, 3, 3, 1],
strides=[1, 2, 2, 1],
padding='SAME',
name='pool1')
# norm1
norm1 = tf.nn.lrn(pool1,
4,
bias=1.0,
alpha=0.001 / 9.0,
beta=0.75,
name='norm1')
# conv2
with tf.variable_scope('conv2') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[5, 5, 64, 128],
stddev=1e-4,
wd=0.0)
conv = tf.nn.conv2d(norm1, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [128], tf.constant_initializer(0.1))
bias = tf.nn.bias_add(conv, biases)
conv2 = tf.nn.relu(bias, name=scope.name)
if dropout:
conv2 = tf.nn.dropout(conv2, 0.3, seed=FLAGS.dropout_seed)
# norm2
norm2 = tf.nn.lrn(conv2,
4,
bias=1.0,
alpha=0.001 / 9.0,
beta=0.75,
name='norm2')
# pool2
pool2 = tf.nn.max_pool(norm2,
ksize=[1, 3, 3, 1],
strides=[1, 2, 2, 1],
padding='SAME',
name='pool2')
# local3
with tf.variable_scope('local3') as scope:
# Move everything into depth so we can perform a single matrix multiply.
reshape = tf.reshape(pool2, [FLAGS.batch_size, -1])
dim = reshape.get_shape()[1].value
weights = _variable_with_weight_decay('weights',
shape=[dim, 384],
stddev=0.04,
wd=0.004)
biases = _variable_on_cpu('biases', [384], tf.constant_initializer(0.1))
local3 = tf.nn.relu(tf.matmul(reshape, weights) + biases, name=scope.name)
if dropout:
local3 = tf.nn.dropout(local3, 0.5, seed=FLAGS.dropout_seed)
# local4
with tf.variable_scope('local4') as scope:
weights = _variable_with_weight_decay('weights',
shape=[384, 192],
stddev=0.04,
wd=0.004)
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.1))
local4 = tf.nn.relu(tf.matmul(local3, weights) + biases, name=scope.name)
if dropout:
local4 = tf.nn.dropout(local4, 0.5, seed=FLAGS.dropout_seed)
# compute logits
with tf.variable_scope('softmax_linear') as scope:
weights = _variable_with_weight_decay('weights',
[192, FLAGS.nb_labels],
stddev=1/192.0,
wd=0.0)
biases = _variable_on_cpu('biases',
[FLAGS.nb_labels],
tf.constant_initializer(0.0))
logits = tf.add(tf.matmul(local4, weights), biases, name=scope.name)
return logits
def inference_deeper(images, dropout=False):
"""Build a deeper CNN model.
Args:
images: Images returned from distorted_inputs() or inputs().
dropout: Boolean controlling whether to use dropout or not
Returns:
Logits
"""
if FLAGS.dataset == 'mnist':
first_conv_shape = [3, 3, 1, 96]
else:
first_conv_shape = [3, 3, 3, 96]
# conv1
with tf.variable_scope('conv1') as scope:
kernel = _variable_with_weight_decay('weights',
shape=first_conv_shape,
stddev=0.05,
wd=0.0)
conv = tf.nn.conv2d(images, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [96], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv1 = tf.nn.relu(bias, name=scope.name)
# conv2
with tf.variable_scope('conv2') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[3, 3, 96, 96],
stddev=0.05,
wd=0.0)
conv = tf.nn.conv2d(conv1, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [96], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv2 = tf.nn.relu(bias, name=scope.name)
# conv3
with tf.variable_scope('conv3') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[3, 3, 96, 96],
stddev=0.05,
wd=0.0)
conv = tf.nn.conv2d(conv2, kernel, [1, 2, 2, 1], padding='SAME')
biases = _variable_on_cpu('biases', [96], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv3 = tf.nn.relu(bias, name=scope.name)
if dropout:
conv3 = tf.nn.dropout(conv3, 0.5, seed=FLAGS.dropout_seed)
# conv4
with tf.variable_scope('conv4') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[3, 3, 96, 192],
stddev=0.05,
wd=0.0)
conv = tf.nn.conv2d(conv3, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv4 = tf.nn.relu(bias, name=scope.name)
# conv5
with tf.variable_scope('conv5') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[3, 3, 192, 192],
stddev=0.05,
wd=0.0)
conv = tf.nn.conv2d(conv4, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv5 = tf.nn.relu(bias, name=scope.name)
# conv6
with tf.variable_scope('conv6') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[3, 3, 192, 192],
stddev=0.05,
wd=0.0)
conv = tf.nn.conv2d(conv5, kernel, [1, 2, 2, 1], padding='SAME')
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.0))
bias = tf.nn.bias_add(conv, biases)
conv6 = tf.nn.relu(bias, name=scope.name)
if dropout:
conv6 = tf.nn.dropout(conv6, 0.5, seed=FLAGS.dropout_seed)
# conv7
with tf.variable_scope('conv7') as scope:
kernel = _variable_with_weight_decay('weights',
shape=[5, 5, 192, 192],
stddev=1e-4,
wd=0.0)
conv = tf.nn.conv2d(conv6, kernel, [1, 1, 1, 1], padding='SAME')
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.1))
bias = tf.nn.bias_add(conv, biases)
conv7 = tf.nn.relu(bias, name=scope.name)
# local1
with tf.variable_scope('local1') as scope:
# Move everything into depth so we can perform a single matrix multiply.
reshape = tf.reshape(conv7, [FLAGS.batch_size, -1])
dim = reshape.get_shape()[1].value
weights = _variable_with_weight_decay('weights',
shape=[dim, 192],
stddev=0.05,
wd=0)
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.1))
local1 = tf.nn.relu(tf.matmul(reshape, weights) + biases, name=scope.name)
# local2
with tf.variable_scope('local2') as scope:
weights = _variable_with_weight_decay('weights',
shape=[192, 192],
stddev=0.05,
wd=0)
biases = _variable_on_cpu('biases', [192], tf.constant_initializer(0.1))
local2 = tf.nn.relu(tf.matmul(local1, weights) + biases, name=scope.name)
if dropout:
local2 = tf.nn.dropout(local2, 0.5, seed=FLAGS.dropout_seed)
# compute logits
with tf.variable_scope('softmax_linear') as scope:
weights = _variable_with_weight_decay('weights',
[192, FLAGS.nb_labels],
stddev=0.05,
wd=0.0)
biases = _variable_on_cpu('biases',
[FLAGS.nb_labels],
tf.constant_initializer(0.0))
logits = tf.add(tf.matmul(local2, weights), biases, name=scope.name)
return logits
def loss_fun(logits, labels):
"""Add L2Loss to all the trainable variables.
Add summary for "Loss" and "Loss/avg".
Args:
logits: Logits from inference().
labels: Labels from distorted_inputs or inputs(). 1-D tensor
of shape [batch_size]
distillation: if set to True, use probabilities and not class labels to
compute softmax loss
Returns:
Loss tensor of type float.
"""
# Calculate the cross entropy between labels and predictions
labels = tf.cast(labels, tf.int64)
cross_entropy = tf.nn.sparse_softmax_cross_entropy_with_logits(
logits=logits, labels=labels, name='cross_entropy_per_example')
# Calculate the average cross entropy loss across the batch.
cross_entropy_mean = tf.reduce_mean(cross_entropy, name='cross_entropy')
# Add to TF collection for losses
tf.add_to_collection('losses', cross_entropy_mean)
# The total loss is defined as the cross entropy loss plus all of the weight
# decay terms (L2 loss).
return tf.add_n(tf.get_collection('losses'), name='total_loss')
def moving_av(total_loss):
"""
Generates moving average for all losses
Args:
total_loss: Total loss from loss().
Returns:
loss_averages_op: op for generating moving averages of losses.
"""
# Compute the moving average of all individual losses and the total loss.
loss_averages = tf.train.ExponentialMovingAverage(0.9, name='avg')
losses = tf.get_collection('losses')
loss_averages_op = loss_averages.apply(losses + [total_loss])
return loss_averages_op
def train_op_fun(total_loss, global_step):
"""Train model.
Create an optimizer and apply to all trainable variables. Add moving
average for all trainable variables.
Args:
total_loss: Total loss from loss().
global_step: Integer Variable counting the number of training steps
processed.
Returns:
train_op: op for training.
"""
# Variables that affect learning rate.
nb_ex_per_train_epoch = int(60000 / FLAGS.nb_teachers)
num_batches_per_epoch = nb_ex_per_train_epoch / FLAGS.batch_size
decay_steps = int(num_batches_per_epoch * FLAGS.epochs_per_decay)
initial_learning_rate = float(FLAGS.learning_rate) / 100.0
# Decay the learning rate exponentially based on the number of steps.
lr = tf.train.exponential_decay(initial_learning_rate,
global_step,
decay_steps,
LEARNING_RATE_DECAY_FACTOR,
staircase=True)
tf.summary.scalar('learning_rate', lr)
# Generate moving averages of all losses and associated summaries.
loss_averages_op = moving_av(total_loss)
# Compute gradients.
with tf.control_dependencies([loss_averages_op]):
opt = tf.train.GradientDescentOptimizer(lr)
grads = opt.compute_gradients(total_loss)
# Apply gradients.
apply_gradient_op = opt.apply_gradients(grads, global_step=global_step)
# Add histograms for trainable variables.
for var in tf.trainable_variables():
tf.summary.histogram(var.op.name, var)
# Track the moving averages of all trainable variables.
variable_averages = tf.train.ExponentialMovingAverage(
MOVING_AVERAGE_DECAY, global_step)
variables_averages_op = variable_averages.apply(tf.trainable_variables())
with tf.control_dependencies([apply_gradient_op, variables_averages_op]):
train_op = tf.no_op(name='train')
return train_op
def _input_placeholder():
"""
This helper function declares a TF placeholder for the graph input data
:return: TF placeholder for the graph input data
"""
if FLAGS.dataset == 'mnist':
image_size = 28
num_channels = 1
else:
image_size = 32
num_channels = 3
# Declare data placeholder
train_node_shape = (FLAGS.batch_size, image_size, image_size, num_channels)
return tf.placeholder(tf.float32, shape=train_node_shape)
def train(images, labels, ckpt_path, dropout=False):
"""
This function contains the loop that actually trains the model.
:param images: a numpy array with the input data
:param labels: a numpy array with the output labels
:param ckpt_path: a path (including name) where model checkpoints are saved
:param dropout: Boolean, whether to use dropout or not
:return: True if everything went well
"""
# Check training data
assert len(images) == len(labels)
assert images.dtype == np.float32
assert labels.dtype == np.int32
# Set default TF graph
with tf.Graph().as_default():
global_step = tf.Variable(0, trainable=False)
# Declare data placeholder
train_data_node = _input_placeholder()
# Create a placeholder to hold labels
train_labels_shape = (FLAGS.batch_size,)
train_labels_node = tf.placeholder(tf.int32, shape=train_labels_shape)
print("Done Initializing Training Placeholders")
# Build a Graph that computes the logits predictions from the placeholder
if FLAGS.deeper:
logits = inference_deeper(train_data_node, dropout=dropout)
else:
logits = inference(train_data_node, dropout=dropout)
# Calculate loss
loss = loss_fun(logits, train_labels_node)
# Build a Graph that trains the model with one batch of examples and
# updates the model parameters.
train_op = train_op_fun(loss, global_step)
# Create a saver.
saver = tf.train.Saver(tf.global_variables())
print("Graph constructed and saver created")
# Build an initialization operation to run below.
init = tf.global_variables_initializer()
# Create and init sessions
sess = tf.Session(config=tf.ConfigProto(log_device_placement=FLAGS.log_device_placement)) #NOLINT(long-line)
sess.run(init)
print("Session ready, beginning training loop")
# Initialize the number of batches
data_length = len(images)
nb_batches = math.ceil(data_length / FLAGS.batch_size)
for step in xrange(FLAGS.max_steps):
# for debug, save start time
start_time = time.time()
# Current batch number
batch_nb = step % nb_batches
# Current batch start and end indices
start, end = utils.batch_indices(batch_nb, data_length, FLAGS.batch_size)
# Prepare dictionnary to feed the session with
feed_dict = {train_data_node: images[start:end],
train_labels_node: labels[start:end]}
# Run training step
_, loss_value = sess.run([train_op, loss], feed_dict=feed_dict)
# Compute duration of training step
duration = time.time() - start_time
# Sanity check
assert not np.isnan(loss_value), 'Model diverged with loss = NaN'
# Echo loss once in a while
if step % 100 == 0:
num_examples_per_step = FLAGS.batch_size
examples_per_sec = num_examples_per_step / duration
sec_per_batch = float(duration)
format_str = ('%s: step %d, loss = %.2f (%.1f examples/sec; %.3f '
'sec/batch)')
print (format_str % (datetime.now(), step, loss_value,
examples_per_sec, sec_per_batch))
# Save the model checkpoint periodically.
if step % 1000 == 0 or (step + 1) == FLAGS.max_steps:
saver.save(sess, ckpt_path, global_step=step)
return True
def softmax_preds(images, ckpt_path, return_logits=False):
"""
Compute softmax activations (probabilities) with the model saved in the path
specified as an argument
:param images: a np array of images
:param ckpt_path: a TF model checkpoint
:param logits: if set to True, return logits instead of probabilities
:return: probabilities (or logits if logits is set to True)
"""
# Compute nb samples and deduce nb of batches
data_length = len(images)
nb_batches = math.ceil(len(images) / FLAGS.batch_size)
# Declare data placeholder
train_data_node = _input_placeholder()
# Build a Graph that computes the logits predictions from the placeholder
if FLAGS.deeper:
logits = inference_deeper(train_data_node)
else:
logits = inference(train_data_node)
if return_logits:
# We are returning the logits directly (no need to apply softmax)
output = logits
else:
# Add softmax predictions to graph: will return probabilities
output = tf.nn.softmax(logits)
# Restore the moving average version of the learned variables for eval.
variable_averages = tf.train.ExponentialMovingAverage(MOVING_AVERAGE_DECAY)
variables_to_restore = variable_averages.variables_to_restore()
saver = tf.train.Saver(variables_to_restore)
# Will hold the result
preds = np.zeros((data_length, FLAGS.nb_labels), dtype=np.float32)
# Create TF session
with tf.Session() as sess:
# Restore TF session from checkpoint file
saver.restore(sess, ckpt_path)
# Parse data by batch
for batch_nb in xrange(0, int(nb_batches+1)):
# Compute batch start and end indices
start, end = utils.batch_indices(batch_nb, data_length, FLAGS.batch_size)
# Prepare feed dictionary
feed_dict = {train_data_node: images[start:end]}
# Run session ([0] because run returns a batch with len 1st dim == 1)
preds[start:end, :] = sess.run([output], feed_dict=feed_dict)[0]
# Reset graph to allow multiple calls
tf.reset_default_graph()
return preds