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Matt Harvey authoredcd5b7202
"""
A collection of models we'll use to attempt to classify videos.
"""
from keras.layers import Dense, Flatten, Dropout, ZeroPadding3D
from keras.layers.recurrent import LSTM
from keras.models import Sequential, load_model
from keras.optimizers import Adam, RMSprop
from keras.layers.wrappers import TimeDistributed
from keras.layers.convolutional import (Conv2D, MaxPooling3D, Conv3D,
MaxPooling2D)
from collections import deque
import sys
class ResearchModels():
def __init__(self, nb_classes, model, seq_length,
saved_model=None, features_length=2048):
"""
`model` = one of:
lstm
lrcn
mlp
conv_3d
c3d
`nb_classes` = the number of classes to predict
`seq_length` = the length of our video sequences
`saved_model` = the path to a saved Keras model to load
"""
# Set defaults.
self.seq_length = seq_length
self.load_model = load_model
self.saved_model = saved_model
self.nb_classes = nb_classes
self.feature_queue = deque()
# Set the metrics. Only use top k if there's a need.
metrics = ['accuracy']
if self.nb_classes >= 10:
metrics.append('top_k_categorical_accuracy')
# Get the appropriate model.
if self.saved_model is not None:
print("Loading model %s" % self.saved_model)
self.model = load_model(self.saved_model)
elif model == 'lstm':
print("Loading LSTM model.")
self.input_shape = (seq_length, features_length)
self.model = self.lstm()
elif model == 'lrcn':
print("Loading CNN-LSTM model.")
self.input_shape = (seq_length, 80, 80, 3)
self.model = self.lrcn()
elif model == 'mlp':
print("Loading simple MLP.")
self.input_shape = (seq_length, features_length)
self.model = self.mlp()
elif model == 'conv_3d':
print("Loading Conv3D")
self.input_shape = (seq_length, 80, 80, 3)
self.model = self.conv_3d()
elif model == 'c3d':
print("Loading C3D")
self.input_shape = (seq_length, 80, 80, 3)
self.model = self.c3d()
else:
print("Unknown network.")
sys.exit()
# Now compile the network.
optimizer = Adam(lr=1e-5, decay=1e-6)
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self.model.compile(loss='categorical_crossentropy', optimizer=optimizer,
metrics=metrics)
print(self.model.summary())
def lstm(self):
"""Build a simple LSTM network. We pass the extracted features from
our CNN to this model predomenently."""
# Model.
model = Sequential()
model.add(LSTM(2048, return_sequences=True, input_shape=self.input_shape,
dropout=0.5))
model.add(Flatten())
model.add(Dense(512, activation='relu'))
model.add(Dropout(0.5))
model.add(Dense(self.nb_classes, activation='softmax'))
return model
def lrcn(self):
"""Build a CNN into RNN.
Starting version from:
https://github.com/udacity/self-driving-car/blob/master/
steering-models/community-models/chauffeur/models.py
Heavily influenced by VGG-16:
https://arxiv.org/abs/1409.1556
Also known as an LRCN:
https://arxiv.org/pdf/1411.4389.pdf
"""
model = Sequential()
model.add(TimeDistributed(Conv2D(32, (7, 7), strides=(2, 2),
activation='relu', padding='same'), input_shape=self.input_shape))
model.add(TimeDistributed(Conv2D(32, (3,3),
kernel_initializer="he_normal", activation='relu')))
model.add(TimeDistributed(MaxPooling2D((2, 2), strides=(2, 2))))
model.add(TimeDistributed(Conv2D(64, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(Conv2D(64, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(MaxPooling2D((2, 2), strides=(2, 2))))
model.add(TimeDistributed(Conv2D(128, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(Conv2D(128, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(MaxPooling2D((2, 2), strides=(2, 2))))
model.add(TimeDistributed(Conv2D(256, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(Conv2D(256, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(MaxPooling2D((2, 2), strides=(2, 2))))
model.add(TimeDistributed(Conv2D(512, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(Conv2D(512, (3,3),
padding='same', activation='relu')))
model.add(TimeDistributed(MaxPooling2D((2, 2), strides=(2, 2))))
model.add(TimeDistributed(Flatten()))
model.add(Dropout(0.5))
model.add(LSTM(256, return_sequences=False, dropout=0.5))
model.add(Dense(self.nb_classes, activation='softmax'))
return model
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def mlp(self):
"""Build a simple MLP. It uses extracted features as the input
because of the otherwise too-high dimensionality."""
# Model.
model = Sequential()
model.add(Flatten(input_shape=self.input_shape))
model.add(Dense(512))
model.add(Dropout(0.5))
model.add(Dense(512))
model.add(Dropout(0.5))
model.add(Dense(self.nb_classes, activation='softmax'))
return model
def conv_3d(self):
"""
Build a 3D convolutional network, based loosely on C3D.
https://arxiv.org/pdf/1412.0767.pdf
"""
# Model.
model = Sequential()
model.add(Conv3D(
32, (3,3,3), activation='relu', input_shape=self.input_shape
))
model.add(MaxPooling3D(pool_size=(1, 2, 2), strides=(1, 2, 2)))
model.add(Conv3D(64, (3,3,3), activation='relu'))
model.add(MaxPooling3D(pool_size=(1, 2, 2), strides=(1, 2, 2)))
model.add(Conv3D(128, (3,3,3), activation='relu'))
model.add(Conv3D(128, (3,3,3), activation='relu'))
model.add(MaxPooling3D(pool_size=(1, 2, 2), strides=(1, 2, 2)))
model.add(Conv3D(256, (2,2,2), activation='relu'))
model.add(Conv3D(256, (2,2,2), activation='relu'))
model.add(MaxPooling3D(pool_size=(1, 2, 2), strides=(1, 2, 2)))
model.add(Flatten())
model.add(Dense(1024))
model.add(Dropout(0.5))
model.add(Dense(1024))
model.add(Dropout(0.5))
model.add(Dense(self.nb_classes, activation='softmax'))
return model
def c3d(self):
"""
Build a 3D convolutional network, aka C3D.
https://arxiv.org/pdf/1412.0767.pdf
With thanks:
https://gist.github.com/albertomontesg/d8b21a179c1e6cca0480ebdf292c34d2
"""
model = Sequential()
# 1st layer group
model.add(Conv3D(64, 3, 3, 3, activation='relu',
border_mode='same', name='conv1',
subsample=(1, 1, 1),
input_shape=self.input_shape))
model.add(MaxPooling3D(pool_size=(1, 2, 2), strides=(1, 2, 2),
border_mode='valid', name='pool1'))
# 2nd layer group
model.add(Conv3D(128, 3, 3, 3, activation='relu',
border_mode='same', name='conv2',
subsample=(1, 1, 1)))
model.add(MaxPooling3D(pool_size=(2, 2, 2), strides=(2, 2, 2),
border_mode='valid', name='pool2'))
# 3rd layer group
model.add(Conv3D(256, 3, 3, 3, activation='relu',
border_mode='same', name='conv3a',
subsample=(1, 1, 1)))
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model.add(Conv3D(256, 3, 3, 3, activation='relu',
border_mode='same', name='conv3b',
subsample=(1, 1, 1)))
model.add(MaxPooling3D(pool_size=(2, 2, 2), strides=(2, 2, 2),
border_mode='valid', name='pool3'))
# 4th layer group
model.add(Conv3D(512, 3, 3, 3, activation='relu',
border_mode='same', name='conv4a',
subsample=(1, 1, 1)))
model.add(Conv3D(512, 3, 3, 3, activation='relu',
border_mode='same', name='conv4b',
subsample=(1, 1, 1)))
model.add(MaxPooling3D(pool_size=(2, 2, 2), strides=(2, 2, 2),
border_mode='valid', name='pool4'))
# 5th layer group
model.add(Conv3D(512, 3, 3, 3, activation='relu',
border_mode='same', name='conv5a',
subsample=(1, 1, 1)))
model.add(Conv3D(512, 3, 3, 3, activation='relu',
border_mode='same', name='conv5b',
subsample=(1, 1, 1)))
model.add(ZeroPadding3D(padding=(0, 1, 1)))
model.add(MaxPooling3D(pool_size=(2, 2, 2), strides=(2, 2, 2),
border_mode='valid', name='pool5'))
model.add(Flatten())
# FC layers group
model.add(Dense(4096, activation='relu', name='fc6'))
model.add(Dropout(0.5))
model.add(Dense(4096, activation='relu', name='fc7'))
model.add(Dropout(0.5))
model.add(Dense(self.nb_classes, activation='softmax'))
return model