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Alexnet

时间:2019-11-23 21:52:28      阅读:103      评论:0      收藏:0      [点我收藏+]

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"""
  AlexNet Keras implementation
   
  """
   
  # Import necessary libs
  import os
  from keras.models import Model
  from keras.layers import Conv2D, MaxPool2D, ZeroPadding2D, Dense, Dropout, \
  Activation, Flatten, BatchNormalization, Input
  from keras.regularizers import l2
  from keras.preprocessing.image import ImageDataGenerator
  from keras.utils import multi_gpu_model
  from keras.callbacks import TensorBoard, EarlyStopping
  import math
   
  os.environ["CUDA_VISIBLE_DEVICES"] = "2, 3"
   
   
  def AlexNet(input_shape=(224, 224, 3), num_classes=10, l2_reg=0.0, weights=None):
  """
  AlexNet model
  :param input_shape: input shape
  :param num_classes: the number of classes
  :param l2_reg:
  :param weights:
  :return: model
  """
  input_layer = Input(shape=input_shape)
   
  # Layer 1
  # In order to get the same size of the paper mentioned, add padding layer first
  x = ZeroPadding2D(padding=(2, 2))(input_layer)
  x = conv_block(x, filters=96, kernel_size=(11, 11),
  strides=(4, 4), padding="valid", l2_reg=l2_reg, name=‘Conv_1_96_11x11_4‘)
  x = MaxPool2D(pool_size=(3, 3), strides=(2, 2), padding="valid", name="maxpool_1_3x3_2")(x)
   
  # Layer 2
  x = conv_block(x, filters=256, kernel_size=(5, 5),
  strides=(1, 1), padding="same", l2_reg=l2_reg, name="Conv_2_256_5x5_1")
  x = MaxPool2D(pool_size=(3, 3), strides=(2, 2), padding="valid", name="maxpool_2_3x3_2")(x)
   
  # Layer 3
  x = conv_block(x, filters=384, kernel_size=(3, 3),
  strides=(1, 1), padding="same", l2_reg=l2_reg, name="Conv_3_384_3x3_1")
   
  # Layer 4
  x = conv_block(x, filters=384, kernel_size=(3, 3),
  strides=(1, 1), padding="same", l2_reg=l2_reg, name="Conv_4_384_3x3_1")
   
  # Layer 5
  x = conv_block(x, filters=256, kernel_size=(3, 3),
  strides=(1, 1), padding="same", l2_reg=l2_reg, name="Conv_5_256_3x3_1")
  x = MaxPool2D(pool_size=(3, 3), strides=(2, 2), padding="valid", name="maxpool_3_3x3_2")(x)
   
  # Layer 6
  x = Flatten()(x)
  x = Dense(units=4096)(x)
  x = BatchNormalization()(x)
  x = Activation(‘relu‘)(x)
   
  # Layer 7
  x = Dense(units=4096)(x)
  x = BatchNormalization()(x)
  x = Activation(‘relu‘)(x)
   
  # Layer 8
  x = Dense(units=num_classes)(x)
  x = BatchNormalization()(x)
  x = Activation("softmax")(x)
   
  if weights is not None:
  x.load_weights(weights)
  model = Model(input_layer, x, name="AlexNet")
  return model
   
   
  def conv_block(layer, filters, kernel_size=(3, 3), strides=(1, 1), padding=‘valid‘, l2_reg=0.0, name=None):
  x = Conv2D(filters=filters,
  kernel_size=kernel_size,
  strides=strides,
  padding=padding,
  kernel_regularizer=l2(l2_reg),
  kernel_initializer="he_normal",
  name=name)(layer)
  x = BatchNormalization()(x)
  x = Activation(‘relu‘)(x)
  return x
   
   
  input_shape = (224, 224, 3)
  num_classes = 10
   
  alexnet = AlexNet(input_shape=input_shape, num_classes=num_classes)
  alexnet.summary()
   
  parallel_model = multi_gpu_model(alexnet, gpus=2)
   
  epochs = 200
  model_name = "AlexNet-2"
  train_dir = r‘/home/lst/datasets/cifar-10-images_train/
  test_dir = r‘/home/lst/datasets/cifar-10-images_test/
  batch_size = 256
  target_weight_height = (224, 224)
   
  parallel_model.compile(loss=[‘categorical_crossentropy‘],
  optimizer=‘adadelta‘,
  metrics=["accuracy"])
  tensorboard = TensorBoard(log_dir=f./logs/{model_name}‘, histogram_freq=0,
  write_graph=True, write_images=False)
   
  early_stopping = EarlyStopping(monitor=‘val_loss‘, patience=20, verbose=1)
   
  train_datagen = ImageDataGenerator(
  rotation_range=40,
  width_shift_range=0.2,
  height_shift_range=0.2,
  rescale=1. / 255,
  shear_range=0.2,
  zoom_range=0.2,
  horizontal_flip=True,
  fill_mode="nearest")
   
  test_datagen = ImageDataGenerator(rescale=1. / 255)
   
  train_generator = train_datagen.flow_from_directory(
  train_dir,
  target_size=target_weight_height,
  batch_size=batch_size,
  class_mode=‘categorical‘)
   
  validation_generator = test_datagen.flow_from_directory(
  test_dir,
  target_size=target_weight_height,
  batch_size=batch_size,
  class_mode=‘categorical‘)
   
  num_train_samples = train_generator.samples
  num_val_samples = validation_generator.samples
   
  history = parallel_model.fit_generator(train_generator,
  validation_data=validation_generator,
  steps_per_epoch=math.ceil(num_train_samples / batch_size),
  validation_steps=math.ceil(num_val_samples / batch_size),
  epochs=epochs,
  callbacks=[tensorboard, early_stopping],
  )
   
  parallel_model.save(f"{model_name}.h5")

Alexnet

标签:oar   his   batch   near   fir   filter   c51   mpi   oss   

原文地址:https://www.cnblogs.com/sun-321/p/11919616.html

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