Merge pull request #23 from titu1994/ror

Added Residual Of Residual Networks
This commit is contained in:
Junwei Pan
2017-02-15 13:02:53 -08:00
committed by GitHub
4 changed files with 348 additions and 1 deletions
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@@ -16,7 +16,7 @@ from keras.datasets import cifar10
from keras.optimizers import Adam
from keras.preprocessing.image import ImageDataGenerator
from keras.utils import np_utils
from keras_contrib.applications.densenet import DenseNet
from keras_contrib.applications import DenseNet
batch_size = 64
nb_classes = 10
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'''
Trains a Residual-of-Residual Network (WRN-40-2) model on the CIFAR-10 Dataset.
Gets a 94.53% accuracy score after 150 epochs.
'''
import numpy as np
import sklearn.metrics as metrics
import keras.callbacks as callbacks
import keras.utils.np_utils as kutils
from keras.datasets import cifar10
from keras.preprocessing.image import ImageDataGenerator
from keras.optimizers import Adam
from keras_contrib.applications import ResidualOfResidual
batch_size = 64
nb_epoch = 150
img_rows, img_cols = 32, 32
(trainX, trainY), (testX, testY) = cifar10.load_data()
trainX = trainX.astype('float32')
testX = testX.astype('float32')
trainX /= 255
testX /= 255
tempY = testY
trainY = kutils.to_categorical(trainY)
testY = kutils.to_categorical(testY)
generator = ImageDataGenerator(rotation_range=15,
width_shift_range=5. / 32,
height_shift_range=5. / 32)
generator.fit(trainX, seed=0)
model = ResidualOfResidual(depth=40, width=2, dropout_rate=0.0, weights='None')
optimizer = Adam(lr=1e-3)
model.compile(loss="categorical_crossentropy", optimizer=optimizer, metrics=["acc"])
print("Finished compiling")
model.fit_generator(generator.flow(trainX, trainY, batch_size=batch_size), samples_per_epoch=len(trainX),
nb_epoch=nb_epoch,
callbacks=[callbacks.ModelCheckpoint("weights/RoR-WRN-40-2-Weights.h5", monitor="val_acc",
save_best_only=True, save_weights_only=True)],
validation_data=(testX, testY),
nb_val_samples=testX.shape[0], verbose=2)
scores = model.evaluate(testX, testY, batch_size)
print("Test loss : ", scores[0])
print("Test accuracy : ", scores[1])
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from .densenet import DenseNet
from .ror import ResidualOfResidual
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# -*- coding: utf-8 -*-
"""Residual of Residual Network models for Keras.
# Reference
- [Residual Networks of Residual Networks: Multilevel Residual Networks](https://arxiv.org/abs/1608.02908)
"""
from __future__ import print_function
from __future__ import absolute_import
from __future__ import division
import warnings
from keras.models import Model
from keras.layers.core import Dense, Dropout, Activation, Flatten
from keras.layers.convolutional import Convolution2D
from keras.layers.pooling import AveragePooling2D, MaxPooling2D
from keras.layers import Input, merge
from keras.layers.normalization import BatchNormalization
from keras.utils.layer_utils import convert_all_kernels_in_model
from keras.utils.data_utils import get_file
from keras.engine.topology import get_source_inputs
from keras.applications.imagenet_utils import _obtain_input_shape
import keras.backend as K
TH_WEIGHTS_PATH = 'https://github.com/titu1994/Residual-of-Residual-Networks/releases/download/v0.2/ror_wrn_40_2_th_kernels_th_dim_ordering.h5'
TF_WEIGHTS_PATH = 'https://github.com/titu1994/Residual-of-Residual-Networks/releases/download/v0.2/ror_wrn_40_2_tf_kernels_tf_dim_ordering.h5'
TH_WEIGHTS_PATH_NO_TOP = 'https://github.com/titu1994/Residual-of-Residual-Networks/releases/download/v0.2/ror_wrn_40_2_th_kernels_th_dim_ordering_no_top.h5'
TF_WEIGHTS_PATH_NO_TOP = 'https://github.com/titu1994/Residual-of-Residual-Networks/releases/download/v0.2/ror_wrn_40_2_tf_kernels_tf_dim_ordering_no_top.h5'
def ResidualOfResidual(depth=40, width=2, dropout_rate=0.0,
include_top=True, weights='cifar10',
input_tensor=None, input_shape=None,
classes=10):
"""Instantiate the Residual of Residual Network architecture,
optionally loading weights pre-trained
on CIFAR-10. Note that when using TensorFlow,
for best performance you should set
`image_dim_ordering="tf"` in your Keras config
at ~/.keras/keras.json.
The model and the weights are compatible with both
TensorFlow and Theano. The dimension ordering
convention used by the model is the one
specified in your Keras config file.
# Arguments
depth: number or layers in the DenseNet
width: width of the network
dropout_rate: dropout rate
include_top: whether to include the fully-connected
layer at the top of the network.
weights: one of `None` (random initialization) or
"cifar10" (pre-training on CIFAR-10)..
input_tensor: optional Keras tensor (i.e. output of `layers.Input()`)
to use as image input for the model.
input_shape: optional shape tuple, only to be specified
if `include_top` is False (otherwise the input shape
has to be `(32, 32, 3)` (with `tf` dim ordering)
or `(3, 32, 32)` (with `th` dim ordering).
It should have exactly 3 inputs channels,
and width and height should be no smaller than 8.
E.g. `(200, 200, 3)` would be one valid value.
classes: optional number of classes to classify images
into, only to be specified if `include_top` is True, and
if no `weights` argument is specified.
# Returns
A Keras model instance.
"""
if weights not in {'cifar10', None}:
raise ValueError('The `weights` argument should be either '
'`None` (random initialization) or `cifar10` '
'(pre-training on CIFAR-10).')
if weights == 'cifar10' and include_top and classes != 10:
raise ValueError('If using `weights` as CIFAR 10 with `include_top`'
' as true, `classes` should be 10')
if (depth - 4) % 6 != 0:
raise ValueError('Depth of the network must be such that (depth - 4)'
'should be divisible by 6.')
# Determine proper input shape
input_shape = _obtain_input_shape(input_shape,
default_size=32,
min_size=8,
dim_ordering=K.image_dim_ordering(),
include_top=include_top)
if input_tensor is None:
img_input = Input(shape=input_shape)
else:
if not K.is_keras_tensor(input_tensor):
img_input = Input(tensor=input_tensor, shape=input_shape)
else:
img_input = input_tensor
x = __create_pre_residual_of_residual(classes, img_input, include_top,
depth, width, dropout_rate)
# Ensure that the model takes into account
# any potential predecessors of `input_tensor`.
if input_tensor is not None:
inputs = get_source_inputs(input_tensor)
else:
inputs = img_input
# Create model.
model = Model(inputs, x, name='residual_of_residual')
# load weights
if weights == 'cifar10':
if (depth == 40) and (width == 2) and (dropout_rate == 0.0):
# Default parameters match. Weights for this model exist:
if K.image_dim_ordering() == 'th':
if include_top:
weights_path = get_file('ror_wrn_40_2_th_kernels_th_dim_ordering.h5',
TH_WEIGHTS_PATH,
cache_subdir='models')
else:
weights_path = get_file('ror_wrn_40_2_th_kernels_th_dim_ordering_no_top.h5',
TH_WEIGHTS_PATH_NO_TOP,
cache_subdir='models')
model.load_weights(weights_path)
if K.backend() == 'tensorflow':
warnings.warn('You are using the TensorFlow backend, yet you '
'are using the Theano '
'image dimension ordering convention '
'(`image_dim_ordering="th"`). '
'For best performance, set '
'`image_dim_ordering="tf"` in '
'your Keras config '
'at ~/.keras/keras.json.')
convert_all_kernels_in_model(model)
else:
if include_top:
weights_path = get_file('ror_wrn_40_2_tf_kernels_tf_dim_ordering_no_top.h5',
TF_WEIGHTS_PATH,
cache_subdir='models')
else:
weights_path = get_file('ror_wrn_40_2_tf_kernels_tf_dim_ordering_no_top.h5',
TF_WEIGHTS_PATH_NO_TOP,
cache_subdir='models')
model.load_weights(weights_path)
if K.backend() == 'theano':
convert_all_kernels_in_model(model)
return model
def __initial_conv_block(input, k=1, dropout=0.0, initial=False):
init = input
channel_axis = 1 if K.image_dim_ordering() == "th" else -1
# Check if input number of filters is same as 16 * k, else create convolution2d for this input
if initial:
if K.image_dim_ordering() == "th":
init = Convolution2D(16 * k, 1, 1, init='he_normal', border_mode='same')(init)
else:
init = Convolution2D(16 * k, 1, 1, init='he_normal', border_mode='same')(init)
x = BatchNormalization(axis=channel_axis)(input)
x = Activation('relu')(x)
x = Convolution2D(16 * k, 3, 3, border_mode='same', init='he_normal')(x)
if dropout > 0.0:
x = Dropout(dropout)(x)
x = BatchNormalization(axis=channel_axis)(x)
x = Activation('relu')(x)
x = Convolution2D(16 * k, 3, 3, border_mode='same', init='he_normal')(x)
m = merge([init, x], mode='sum')
return m
def __conv_block(input, nb_filters=32, k=1, dropout=0.0):
init = input
channel_axis = 1 if K.image_dim_ordering() == "th" else -1
# Check if input number of filters is same as 32 * k, else create convolution2d for this input
if K.image_dim_ordering() == "th":
if init._keras_shape[1] != nb_filters * k:
init = Convolution2D(nb_filters * k, 1, 1, init='he_normal', border_mode='same')(init)
else:
if init._keras_shape[-1] != nb_filters * k:
init = Convolution2D(nb_filters * k, 1, 1, init='he_normal', border_mode='same')(init)
x = BatchNormalization(axis=channel_axis)(input)
x = Activation('relu')(x)
x = Convolution2D(nb_filters * k, 3, 3, border_mode='same', init='he_normal')(x)
if dropout > 0.0:
x = Dropout(dropout)(x)
x = BatchNormalization(axis=channel_axis)(x)
x = Activation('relu')(x)
x = Convolution2D(nb_filters * k, 3, 3, border_mode='same', init='he_normal')(x)
m = merge([init, x], mode='sum')
return m
def __create_pre_residual_of_residual(nb_classes, img_input, include_top, depth=28, width=1, dropout=0.0):
'''
Creates a Residual Network of Residual Network with specified parameters
Example : To create a Pre-RoR model, use k = 1
model = ResidualOfResidual(depth=28, width=1) # Pre-RoR-3
To create a RoR-WRN model, use k > 1
model = ResidualOfResidual(depth=28, width=10) # Pre-RoR-3, RoR-3-WRN-28-10
Args:
nb_classes: number of classes
img_input: tuple of shape (channels, rows, columns) or (rows, columns, channels)
include_top: flag to include the final Dense layer
depth: depth of the network
width: width of the network
dropout: Adds dropout if value is greater than 0.0.
Note : Generally not used in RoR
Returns: a Keras Model
'''
N = (depth - 4) // 6
channel_axis = 1 if K.image_dim_ordering() == "th" else -1
# Initial convolution layer
x = Convolution2D(16, 3, 3, border_mode='same', init='he_normal')(img_input)
nb_conv = 4 # Dont count 4 long residual connections in WRN models
conv0_level1_shortcut = Convolution2D(64 * width, 1, 1, border_mode='same', subsample=(4, 4),
name='conv0_level1_shortcut')(x)
conv1_level2_shortcut = Convolution2D(16 * width, 1, 1, border_mode='same',
name='conv1_level2_shortcut')(x)
for i in range(N):
initial = (i == 0)
x = __initial_conv_block(x, k=width, dropout=dropout, initial=initial)
nb_conv += 2
# Add Level 2 shortcut
x = merge([x, conv1_level2_shortcut], mode='sum')
x = MaxPooling2D((2, 2))(x)
conv2_level2_shortcut = Convolution2D(32 * width, 1, 1, border_mode='same',
name='conv2_level2_shortcut')(x)
for i in range(N):
x = __conv_block(x, k=width, dropout=dropout)
nb_conv += 2
# Add Level 2 shortcut
x = merge([x, conv2_level2_shortcut], mode='sum')
x = MaxPooling2D((2, 2))(x)
conv3_level2_shortcut = Convolution2D(64 * width, 1, 1, border_mode='same',
name='conv3_level2_shortcut')(x)
for i in range(N):
x = __conv_block(x, nb_filters=64, k=width, dropout=dropout)
nb_conv += 2
# Add Level 2 shortcut
x = merge([x, conv3_level2_shortcut], mode='sum')
# Add Level 1 shortcut
x = merge([x, conv0_level1_shortcut], mode='sum')
x = BatchNormalization(axis=channel_axis)(x)
x = Activation('relu')(x)
x = AveragePooling2D((8, 8))(x)
if include_top:
x = Flatten()(x)
x = Dense(nb_classes, activation='softmax')(x)
return x