In [2]:
from __future__ import absolute_import
from __future__ import print_function
from keras.datasets import cifar10
from keras.preprocessing.image import ImageDataGenerator
from keras.models import Sequential
from keras.layers.core import Dense, Dropout, Activation, Flatten
from keras.layers.convolutional import Convolution2D, MaxPooling2D
from keras.optimizers import SGD, Adadelta, Adagrad
from keras.utils import np_utils, generic_utils
from six.moves import range
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batch_size = 32
nb_classes = 10
nb_epoch = 2
data_augmentation = True
# the data, shuffled and split between tran and test sets
(X_train, y_train), (X_test, y_test) = cifar10.load_data(test_split=0.1)
print(X_train.shape[0], 'train samples')
print(X_test.shape[0], 'test samples')
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# convert class vectors to binary class matrices
Y_train = np_utils.to_categorical(y_train, nb_classes)
Y_test = np_utils.to_categorical(y_test, nb_classes)
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X_train[0].shape
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Y_train.shape
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In [6]:
Y_train[0]
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model = Sequential()
model.add(Convolution2D(32, 3, 3, 3, border_mode='full'))
model.add(Activation('relu'))
model.add(Convolution2D(32, 32, 3, 3))
model.add(Activation('relu'))
model.add(MaxPooling2D(poolsize=(2, 2)))
model.add(Dropout(0.25))
model.add(Convolution2D(64, 32, 3, 3, border_mode='full'))
model.add(Activation('relu'))
model.add(Convolution2D(64, 64, 3, 3))
model.add(Activation('relu'))
model.add(MaxPooling2D(poolsize=(2, 2)))
model.add(Dropout(0.25))
model.add(Flatten())
model.add(Dense(64*8*8, 512, init='normal'))
model.add(Activation('relu'))
model.add(Dropout(0.5))
model.add(Dense(512, nb_classes, init='normal'))
model.add(Activation('softmax'))
# let's train the model using SGD + momentum (how original).
sgd = SGD(lr=0.01, decay=1e-6, momentum=0.9, nesterov=True)
model.compile(loss='categorical_crossentropy', optimizer=sgd)
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if not data_augmentation:
print("Not using data augmentation or normalization")
X_train = X_train.astype("float32")
X_test = X_test.astype("float32")
X_train /= 255
X_test /= 255
model.fit(X_train, Y_train, batch_size=batch_size, nb_epoch=10)
score = model.evaluate(X_test, Y_test, batch_size=batch_size)
print('Test score:', score)
else:
print("Using real time data augmentation")
# this will do preprocessing and realtime data augmentation
datagen = ImageDataGenerator(
featurewise_center=True, # set input mean to 0 over the dataset
samplewise_center=False, # set each sample mean to 0
featurewise_std_normalization=True, # divide inputs by std of the dataset
samplewise_std_normalization=False, # divide each input by its std
zca_whitening=False, # apply ZCA whitening
rotation_range=20, # randomly rotate images in the range (degrees, 0 to 180)
width_shift_range=0.2, # randomly shift images horizontally (fraction of total width)
height_shift_range=0.2, # randomly shift images vertically (fraction of total height)
horizontal_flip=True, # randomly flip images
vertical_flip=False) # randomly flip images
# compute quantities required for featurewise normalization
# (std, mean, and principal components if ZCA whitening is applied)
datagen.fit(X_train)
for e in range(nb_epoch):
print('-'*40)
print('Epoch', e)
print('-'*40)
print("Training...")
# batch train with realtime data augmentation
progbar = generic_utils.Progbar(X_train.shape[0])
for X_batch, Y_batch in datagen.flow(X_train, Y_train):
loss = model.train(X_batch, Y_batch)
progbar.add(X_batch.shape[0], values=[("train loss", loss)])
print("Testing...")
# test time!
progbar = generic_utils.Progbar(X_test.shape[0])
for X_batch, Y_batch in datagen.flow(X_test, Y_test):
score = model.test(X_batch, Y_batch)
progbar.add(X_batch.shape[0], values=[("test loss", score)])
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X_train.shape
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