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ImageDataGenerator和flow()有什么用

發(fā)布時間:2020-07-06 14:02:32 來源:億速云 閱讀:365 作者:清晨 欄目:開發(fā)技術(shù)

這篇文章主要介紹ImageDataGenerator和flow()有什么用,文中介紹的非常詳細(xì),具有一定的參考價值,感興趣的小伙伴們一定要看完!

ImageDataGenerator的參數(shù)自己看文檔

from keras.preprocessing import image
import numpy as np

X_train=np.ones((3,123,123,1))
Y_train=np.array([[1],[2],[2]])
generator=image.ImageDataGenerator(featurewise_center=False,
  samplewise_center=False,
  featurewise_std_normalization=False,
  samplewise_std_normalization=False,
  zca_whitening=False,
  zca_epsilon=1e-6,
  rotation_range=180,
  width_shift_range=0.2,
  height_shift_range=0.2,
  shear_range=0,
  zoom_range=0.001,
  channel_shift_range=0,
  fill_mode='nearest',
  cval=0.,
  horizontal_flip=True,
  vertical_flip=True,
  rescale=None,
  preprocessing_function=None,
  data_format='channels_last')

a=generator.flow(X_train,Y_train,batch_size=20)#生成的是一個迭代器,可直接用于for循環(huán)
'''
batch_size如果小于X的第一維m,next生成的多維矩陣的第一維是為batch_size,輸出是從輸入中隨機(jī)選取batch_size個數(shù)據(jù)
batch_size如果大于X的第一維m,next生成的多維矩陣的第一維是m,輸出是m個數(shù)據(jù),不過順序隨機(jī)
,輸出的X,Y是一一對對應(yīng)的
如果要直接用于tf.placeholder(),要求生成的矩陣和要與tf.placeholder相匹配

'''
X,Y=next(a)

print(Y)
X,Y=next(a)

print(Y)
X,Y=next(a)

print(Y)
X,Y=next(a)

輸出

[[2]
 [1]
 [2]]

[[2]
 [2]
 [1]]

[[2]
 [2]
 [1]]

[[2]
 [2]
 [1]]

補(bǔ)充知識:tensorflow 與keras 混用之坑

在使用tensorflow與keras混用是model.save 是正常的但是在load_model的時候報錯了在這里mark 一下

其中錯誤為:TypeError: tuple indices must be integers, not list

再一一番百度后無結(jié)果,上谷歌后找到了類似的問題。但是是一對鳥文不知道什么東西(翻譯后發(fā)現(xiàn)是俄文)。后來谷歌翻譯了一下找到了解決方法。故將原始問題文章貼上來警示一下

原訓(xùn)練代碼

from tensorflow.python.keras.preprocessing.image import ImageDataGenerator
from tensorflow.python.keras.models import Sequential
from tensorflow.python.keras.layers import Conv2D, MaxPooling2D, BatchNormalization
from tensorflow.python.keras.layers import Activation, Dropout, Flatten, Dense
 
#Каталог с данными для обучения
train_dir = 'train'
# Каталог с данными для проверки
val_dir = 'val'
# Каталог с данными для тестирования
test_dir = 'val'
 
# Размеры изображения
img_width, img_height = 800, 800
# Размерность тензора на основе изображения для входных данных в нейронную сеть
# backend Tensorflow, channels_last
input_shape = (img_width, img_height, 3)
# Количество эпох
epochs = 1
# Размер мини-выборки
batch_size = 4
# Количество изображений для обучения
nb_train_samples = 300
# Количество изображений для проверки
nb_validation_samples = 25
# Количество изображений для тестирования
nb_test_samples = 25
 
model = Sequential()
 
model.add(Conv2D(32, (7, 7), padding="same", input_shape=input_shape))
model.add(BatchNormalization())
model.add(Activation('tanh'))
model.add(MaxPooling2D(pool_size=(10, 10)))
 
model.add(Conv2D(64, (5, 5), padding="same"))
model.add(BatchNormalization())
model.add(Activation('tanh'))
model.add(MaxPooling2D(pool_size=(10, 10)))
 
model.add(Flatten())
model.add(Dense(512))
model.add(Activation('relu'))
model.add(Dropout(0.5))
model.add(Dense(10, activation='softmax'))
 
model.compile(loss='categorical_crossentropy',
       optimizer="Nadam",
       metrics=['accuracy'])
print(model.summary())
datagen = ImageDataGenerator(rescale=1. / 255)
 
train_generator = datagen.flow_from_directory(
  train_dir,
  target_size=(img_width, img_height),
  batch_size=batch_size,
  class_mode='categorical')
 
val_generator = datagen.flow_from_directory(
  val_dir,
  target_size=(img_width, img_height),
  batch_size=batch_size,
  class_mode='categorical')
 
test_generator = datagen.flow_from_directory(
  test_dir,
  target_size=(img_width, img_height),
  batch_size=batch_size,
  class_mode='categorical')
 
model.fit_generator(
  train_generator,
  steps_per_epoch=nb_train_samples // batch_size,
  epochs=epochs,
  validation_data=val_generator,
  validation_steps=nb_validation_samples // batch_size)
 
print('Сохраняем сеть')
model.save("grib.h6")
print("Сохранение завершено!")

模型載入

from tensorflow.python.keras.preprocessing.image import ImageDataGenerator
from tensorflow.python.keras.models import Sequential
from tensorflow.python.keras.layers import Conv2D, MaxPooling2D, BatchNormalization
from tensorflow.python.keras.layers import Activation, Dropout, Flatten, Dense
from keras.models import load_model
 
print("Загрузка сети")
model = load_model("grib.h6")
print("Загрузка завершена!")

報錯

/usr/bin/python3.5 /home/disk2/py/neroset/do.py
/home/mama/.local/lib/python3.5/site-packages/h6py/__init__.py:36: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`.
 from ._conv import register_converters as _register_converters
Using TensorFlow backend.
Загрузка сети
Traceback (most recent call last):
 File "/home/disk2/py/neroset/do.py", line 13, in <module>
  model = load_model("grib.h6")
 File "/usr/local/lib/python3.5/dist-packages/keras/models.py", line 243, in load_model
  model = model_from_config(model_config, custom_objects=custom_objects)
 File "/usr/local/lib/python3.5/dist-packages/keras/models.py", line 317, in model_from_config
  return layer_module.deserialize(config, custom_objects=custom_objects)
 File "/usr/local/lib/python3.5/dist-packages/keras/layers/__init__.py", line 55, in deserialize
  printable_module_name='layer')
 File "/usr/local/lib/python3.5/dist-packages/keras/utils/generic_utils.py", line 144, in deserialize_keras_object
  list(custom_objects.items())))
 File "/usr/local/lib/python3.5/dist-packages/keras/models.py", line 1350, in from_config
  model.add(layer)
 File "/usr/local/lib/python3.5/dist-packages/keras/models.py", line 492, in add
  output_tensor = layer(self.outputs[0])
 File "/usr/local/lib/python3.5/dist-packages/keras/engine/topology.py", line 590, in __call__
  self.build(input_shapes[0])
 File "/usr/local/lib/python3.5/dist-packages/keras/layers/normalization.py", line 92, in build
  dim = input_shape[self.axis]
TypeError: tuple indices must be integers or slices, not list
 
Process finished with exit code 1

戰(zhàn)斗種族解釋

убераю BatchNormalization всё работает хорошо. Не подскажите в чём ошибкаВыяснил что сохранение keras и нормализация tensorflow не работают вместе нужно просто изменить строку импорта.(譯文:整理BatchNormalization一切正常。 不要告訴我錯誤是什么?我發(fā)現(xiàn)保存keras和規(guī)范化tensorflow不能一起工作;只需更改導(dǎo)入字符串即可。)

強(qiáng)調(diào)文本 強(qiáng)調(diào)文本

keras.preprocessing.image import ImageDataGenerator
keras.models import Sequential
keras.layers import Conv2D, MaxPooling2D, BatchNormalization
keras.layers import Activation, Dropout, Flatten, Dense

以上是ImageDataGenerator和flow()有什么用的所有內(nèi)容,感謝各位的閱讀!希望分享的內(nèi)容對大家有幫助,更多相關(guān)知識,歡迎關(guān)注億速云行業(yè)資訊頻道!

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