DeepLearningExamples/TensorFlow/Classification/ConvNets/model/resnet.py
2021-11-02 06:53:59 -07:00

513 lines
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Python
Executable file

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2018, NVIDIA CORPORATION. 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 print_function
import tensorflow as tf
from utils import hvd_wrapper as hvd
import dllogger
from model import layers
from model import blocks
from utils import var_storage
from utils.data_utils import normalized_inputs
from utils.learning_rate import learning_rate_scheduler
from utils.optimizers import FixedLossScalerOptimizer
__all__ = [
'ResnetModel',
]
class ResnetModel(object):
"""Resnet cnn network configuration."""
def __init__(
self,
model_name,
n_classes,
layers_count,
layers_depth,
expansions,
compute_format='NCHW',
input_format='NHWC',
weight_init='fan_out',
dtype=tf.float32,
use_dali=False,
use_cpu=False,
cardinality=1,
use_se=False,
se_ratio=1,
):
self.model_hparams = tf.contrib.training.HParams(
n_classes=n_classes,
compute_format=compute_format,
input_format=input_format,
dtype=dtype,
layers_count=layers_count,
layers_depth=layers_depth,
expansions=expansions,
model_name=model_name,
use_dali=use_dali,
use_cpu=use_cpu,
cardinality=cardinality,
use_se=use_se,
se_ratio=se_ratio
)
self.batch_norm_hparams = tf.contrib.training.HParams(
decay=0.9,
epsilon=1e-5,
scale=True,
center=True,
param_initializers={
'beta': tf.constant_initializer(0.0),
'gamma': tf.constant_initializer(1.0),
'moving_mean': tf.constant_initializer(0.0),
'moving_variance': tf.constant_initializer(1.0)
},
)
self.conv2d_hparams = tf.contrib.training.HParams(
kernel_initializer=tf.compat.v1.variance_scaling_initializer(
scale=2.0, distribution='truncated_normal', mode=weight_init
),
bias_initializer=tf.constant_initializer(0.0)
)
self.dense_hparams = tf.contrib.training.HParams(
kernel_initializer=tf.compat.v1.variance_scaling_initializer(
scale=2.0, distribution='truncated_normal', mode=weight_init
),
bias_initializer=tf.constant_initializer(0.0)
)
if hvd.rank() == 0:
print("Model HParams:")
print("Name", model_name)
print("Number of classes", n_classes)
print("Compute_format", compute_format)
print("Input_format", input_format)
print("dtype", str(dtype))
def __call__(self, features, labels, mode, params):
if mode == tf.estimator.ModeKeys.TRAIN:
mandatory_params = [
"batch_size", "lr_init", "num_gpus", "steps_per_epoch", "momentum", "weight_decay", "loss_scale",
"label_smoothing"
]
for p in mandatory_params:
if p not in params:
raise RuntimeError("Parameter {} is missing.".format(p))
if mode == tf.estimator.ModeKeys.TRAIN and not self.model_hparams.use_dali:
with tf.device('/cpu:0'):
# Stage inputs on the host
cpu_prefetch_op, (features, labels) = self._stage([features, labels])
if not self.model_hparams.use_cpu:
with tf.device('/gpu:0'):
# Stage inputs to the device
gpu_prefetch_op, (features, labels) = self._stage([features, labels])
main_device = "/gpu:0" if not self.model_hparams.use_cpu else "/cpu:0"
with tf.device(main_device):
if features.dtype != self.model_hparams.dtype:
features = tf.cast(features, self.model_hparams.dtype)
# Subtract mean per channel
# and enforce values between [-1, 1]
if not self.model_hparams.use_dali:
features = normalized_inputs(features)
mixup = 0
eta = 0
if mode == tf.estimator.ModeKeys.TRAIN:
eta = params['label_smoothing']
mixup = params['mixup']
if mode != tf.estimator.ModeKeys.PREDICT:
n_cls = self.model_hparams.n_classes
one_hot_smoothed_labels = tf.one_hot(labels, n_cls,
on_value=1 - eta + eta / n_cls, off_value=eta / n_cls)
if mixup != 0:
print("Using mixup training with beta=", params['mixup'])
beta_distribution = tf.distributions.Beta(params['mixup'], params['mixup'])
feature_coefficients = beta_distribution.sample(sample_shape=[params['batch_size'], 1, 1, 1])
reversed_feature_coefficients = tf.subtract(
tf.ones(shape=feature_coefficients.shape), feature_coefficients
)
rotated_features = tf.reverse(features, axis=[0])
features = feature_coefficients * features + reversed_feature_coefficients * rotated_features
label_coefficients = tf.squeeze(feature_coefficients, axis=[2, 3])
rotated_labels = tf.reverse(one_hot_smoothed_labels, axis=[0])
reversed_label_coefficients = tf.subtract(
tf.ones(shape=label_coefficients.shape), label_coefficients
)
one_hot_smoothed_labels = label_coefficients * one_hot_smoothed_labels + reversed_label_coefficients * rotated_labels
# Update Global Step
global_step = tf.train.get_or_create_global_step()
tf.identity(global_step, name="global_step_ref")
tf.identity(features, name="features_ref")
if mode == tf.estimator.ModeKeys.TRAIN:
tf.identity(labels, name="labels_ref")
probs, logits = self.build_model(
features,
training=mode == tf.estimator.ModeKeys.TRAIN,
reuse=False,
use_final_conv=params['use_final_conv']
)
if params['use_final_conv']:
logits = tf.squeeze(logits, axis=[-2, -1])
y_preds = tf.argmax(logits, axis=1, output_type=tf.int32)
# Check the output dtype, shall be FP32 in training
assert (probs.dtype == tf.float32)
assert (logits.dtype == tf.float32)
assert (y_preds.dtype == tf.int32)
tf.identity(logits, name="logits_ref")
tf.identity(probs, name="probs_ref")
tf.identity(y_preds, name="y_preds_ref")
#if mode == tf.estimator.ModeKeys.TRAIN:
#
# assert (len(tf.trainable_variables()) == 161)
#
#else:
#
# assert (len(tf.trainable_variables()) == 0)
if mode == tf.estimator.ModeKeys.TRAIN and params['quantize']:
dllogger.log(data={"QUANTIZATION AWARE TRAINING ENABLED": True}, step=tuple())
if params['symmetric']:
dllogger.log(data={"MODE": "USING SYMMETRIC MODE"}, step=tuple())
tf.contrib.quantize.experimental_create_training_graph(
tf.get_default_graph(),
symmetric=True,
use_qdq=params['use_qdq'],
quant_delay=params['quant_delay']
)
else:
dllogger.log(data={"MODE": "USING ASSYMETRIC MODE"}, step=tuple())
tf.contrib.quantize.create_training_graph(
tf.get_default_graph(), quant_delay=params['quant_delay'], use_qdq=params['use_qdq']
)
# Fix for restoring variables during fine-tuning of Resnet
if 'finetune_checkpoint' in params.keys():
train_vars = tf.trainable_variables()
train_var_dict = {}
for var in train_vars:
train_var_dict[var.op.name] = var
dllogger.log(data={"Restoring variables from checkpoint": params['finetune_checkpoint']}, step=tuple())
tf.train.init_from_checkpoint(params['finetune_checkpoint'], train_var_dict)
if mode == tf.estimator.ModeKeys.PREDICT:
predictions = {'classes': y_preds, 'probabilities': probs}
return tf.estimator.EstimatorSpec(
mode=mode,
predictions=predictions,
export_outputs={'predict': tf.estimator.export.PredictOutput(predictions)}
)
else:
with tf.device(main_device):
if mode == tf.estimator.ModeKeys.TRAIN:
acc_top1 = tf.nn.in_top_k(predictions=logits, targets=labels, k=1)
acc_top5 = tf.nn.in_top_k(predictions=logits, targets=labels, k=5)
else:
acc_top1, acc_top1_update_op = tf.metrics.mean(
tf.nn.in_top_k(predictions=logits, targets=labels, k=1)
)
acc_top5, acc_top5_update_op = tf.metrics.mean(
tf.nn.in_top_k(predictions=logits, targets=labels, k=5)
)
tf.identity(acc_top1, name="acc_top1_ref")
tf.identity(acc_top5, name="acc_top5_ref")
predictions = {
'classes': y_preds,
'probabilities': probs,
'accuracy_top1': acc_top1,
'accuracy_top5': acc_top5
}
cross_entropy = tf.losses.softmax_cross_entropy(logits=logits, onehot_labels=one_hot_smoothed_labels)
assert (cross_entropy.dtype == tf.float32)
tf.identity(cross_entropy, name='cross_entropy_loss_ref')
def loss_filter_fn(name):
"""we don't need to compute L2 loss for BN and bias (eq. to add a cste)"""
return all(
[
tensor_name not in name.lower()
# for tensor_name in ["batchnorm", "batch_norm", "batch_normalization", "bias"]
for tensor_name in ["batchnorm", "batch_norm", "batch_normalization"]
]
)
filtered_params = [tf.cast(v, tf.float32) for v in tf.trainable_variables() if loss_filter_fn(v.name)]
if len(filtered_params) != 0:
l2_loss_per_vars = [tf.nn.l2_loss(v) for v in filtered_params]
l2_loss = tf.multiply(tf.add_n(l2_loss_per_vars), params["weight_decay"])
else:
l2_loss = tf.zeros(shape=(), dtype=tf.float32)
assert (l2_loss.dtype == tf.float32)
tf.identity(l2_loss, name='l2_loss_ref')
total_loss = tf.add(cross_entropy, l2_loss, name="total_loss")
assert (total_loss.dtype == tf.float32)
tf.identity(total_loss, name='total_loss_ref')
tf.summary.scalar('cross_entropy', cross_entropy)
tf.summary.scalar('l2_loss', l2_loss)
tf.summary.scalar('total_loss', total_loss)
if mode == tf.estimator.ModeKeys.TRAIN:
with tf.device("/cpu:0"):
learning_rate = learning_rate_scheduler(
lr_init=params["lr_init"],
lr_warmup_epochs=params["lr_warmup_epochs"],
global_step=global_step,
batch_size=params["batch_size"],
num_batches_per_epoch=params["steps_per_epoch"],
num_decay_steps=params["num_decay_steps"],
num_gpus=params["num_gpus"],
use_cosine_lr=params["use_cosine_lr"]
)
tf.identity(learning_rate, name='learning_rate_ref')
tf.summary.scalar('learning_rate', learning_rate)
optimizer = tf.train.MomentumOptimizer(learning_rate=learning_rate, momentum=params["momentum"])
if params["apply_loss_scaling"]:
optimizer = FixedLossScalerOptimizer(optimizer, scale=params["loss_scale"])
if hvd.size() > 1:
optimizer = hvd.hvd_global_object.DistributedOptimizer(optimizer)
update_ops = tf.get_collection(tf.GraphKeys.UPDATE_OPS)
if mode != tf.estimator.ModeKeys.TRAIN:
update_ops += [acc_top1_update_op, acc_top5_update_op]
deterministic = True
gate_gradients = (tf.compat.v1.train.Optimizer.GATE_OP if deterministic else tf.compat.v1.train.Optimizer.GATE_NONE)
backprop_op = optimizer.minimize(total_loss, gate_gradients=gate_gradients, global_step=global_step)
if self.model_hparams.use_dali:
train_ops = tf.group(backprop_op, update_ops, name='train_ops')
elif self.model_hparams.use_cpu:
train_ops = tf.group(
backprop_op, cpu_prefetch_op, update_ops, name='train_ops'
)
else:
train_ops = tf.group(
backprop_op, cpu_prefetch_op, gpu_prefetch_op, update_ops, name='train_ops'
)
return tf.estimator.EstimatorSpec(mode=mode, loss=total_loss, train_op=train_ops)
elif mode == tf.estimator.ModeKeys.EVAL:
eval_metrics = {
"top1_accuracy": (acc_top1, acc_top1_update_op),
"top5_accuracy": (acc_top5, acc_top5_update_op)
}
return tf.estimator.EstimatorSpec(
mode=mode, predictions=predictions, loss=total_loss, eval_metric_ops=eval_metrics
)
else:
raise NotImplementedError('Unknown mode {}'.format(mode))
@staticmethod
def _stage(tensors):
"""Stages the given tensors in a StagingArea for asynchronous put/get.
"""
stage_area = tf.contrib.staging.StagingArea(
dtypes=[tensor.dtype for tensor in tensors], shapes=[tensor.get_shape() for tensor in tensors]
)
put_op = stage_area.put(tensors)
get_tensors = stage_area.get()
tf.add_to_collection('STAGING_AREA_PUTS', put_op)
return put_op, get_tensors
def build_model(self, inputs, training=True, reuse=False, use_final_conv=False):
with var_storage.model_variable_scope(
self.model_hparams.model_name, reuse=reuse, dtype=self.model_hparams.dtype
):
with tf.variable_scope("input_reshape"):
if self.model_hparams.input_format == 'NHWC' and self.model_hparams.compute_format == 'NCHW':
# Reshape inputs: NHWC => NCHW
inputs = tf.transpose(inputs, [0, 3, 1, 2])
elif self.model_hparams.input_format == 'NCHW' and self.model_hparams.compute_format == 'NHWC':
# Reshape inputs: NCHW => NHWC
inputs = tf.transpose(inputs, [0, 2, 3, 1])
if self.model_hparams.dtype != inputs.dtype:
inputs = tf.cast(inputs, self.model_hparams.dtype)
net = blocks.conv2d_block(
inputs,
n_channels=64,
kernel_size=(7, 7),
strides=(2, 2),
mode='SAME',
use_batch_norm=True,
activation='relu',
is_training=training,
data_format=self.model_hparams.compute_format,
conv2d_hparams=self.conv2d_hparams,
batch_norm_hparams=self.batch_norm_hparams,
name='conv2d'
)
net = layers.max_pooling2d(
net,
pool_size=(3, 3),
strides=(2, 2),
padding='SAME',
data_format=self.model_hparams.compute_format,
name="max_pooling2d",
)
model_bottlenecks = self.model_hparams.layers_depth
for block_id, block_bottleneck in enumerate(model_bottlenecks):
for layer_id in range(self.model_hparams.layers_count[block_id]):
stride = 2 if (layer_id == 0 and block_id != 0) else 1
net = blocks.bottleneck_block(
inputs=net,
depth=block_bottleneck * self.model_hparams.expansions,
depth_bottleneck=block_bottleneck,
cardinality=self.model_hparams.cardinality,
stride=stride,
training=training,
data_format=self.model_hparams.compute_format,
conv2d_hparams=self.conv2d_hparams,
batch_norm_hparams=self.batch_norm_hparams,
block_name="btlnck_block_%d_%d" % (block_id, layer_id),
use_se=self.model_hparams.use_se,
ratio=self.model_hparams.se_ratio
)
with tf.variable_scope("output"):
net = layers.reduce_mean(
net, keepdims=False, data_format=self.model_hparams.compute_format, name='spatial_mean'
)
if use_final_conv:
logits = layers.conv2d(
net,
n_channels=self.model_hparams.n_classes,
kernel_size=(1, 1),
strides=(1, 1),
padding='SAME',
data_format=self.model_hparams.compute_format,
dilation_rate=(1, 1),
use_bias=True,
kernel_initializer=self.dense_hparams.kernel_initializer,
bias_initializer=self.dense_hparams.bias_initializer,
trainable=training,
name='dense'
)
else:
logits = layers.dense(
inputs=net,
units=self.model_hparams.n_classes,
use_bias=True,
trainable=training,
kernel_initializer=self.dense_hparams.kernel_initializer,
bias_initializer=self.dense_hparams.bias_initializer
)
if logits.dtype != tf.float32:
logits = tf.cast(logits, tf.float32)
axis = 3 if self.model_hparams.compute_format=="NHWC" and use_final_conv else 1
probs = layers.softmax(logits, name="softmax", axis=axis)
return probs, logits
model_architectures = {
'resnet50': {
'layers': [3, 4, 6, 3],
'widths': [64, 128, 256, 512],
'expansions': 4,
},
'resnext101-32x4d': {
'layers': [3, 4, 23, 3],
'widths': [128, 256, 512, 1024],
'expansions': 2,
'cardinality': 32,
},
'se-resnext101-32x4d': {
'cardinality': 32,
'layers': [3, 4, 23, 3],
'widths': [128, 256, 512, 1024],
'expansions': 2,
'use_se': True,
'se_ratio': 16,
},
}