首页 > 解决方案 > 为什么我的 acc 总是更高但我的 val_acc 很小?

问题描述

我尝试训练 14000 个训练数据集和 3500 个验证数据集,但是为什么每次训练我总是得到高精度结果而验证部分非常小

那么如果我希望验证的结果接近训练的准确性并为每个时期提供重要的补充,我该怎么办

是否必须增加或减少一些东西?[对不起英语不好]

from keras.models import Sequential
from keras.layers import Conv2D
from keras.layers import MaxPooling2D
from keras.layers import Flatten
from keras.layers import Dense

classifier = Sequential()


classifier.add(Conv2D(16, (3, 3), input_shape = (64, 64, 3), activation = 'relu'))
`classifier.add(MaxPooling2D(pool_size = (2, 2)))


classifier.add(Conv2D(32, (3, 3), activation = 'relu'))
classifier.add(MaxPooling2D(pool_size = (2, 2)))`


classifier.add(Conv2D(64, (3, 3), activation = 'relu'))
classifier.add(MaxPooling2D(pool_size = (2, 2)))

classifier.add(Dense(units = 128, activation = 'relu'))
classifier.add(Dense(units = 1, activation = 'sigmoid'))

classifier.add(Flatten())

classifier.add(Dense(units = 128, activation = 'relu'))
classifier.add(Dense(units = 1, activation = 'sigmoid'))

classifier.compile(optimizer = 'adam', loss = 'binary_crossentropy', metrics = ['accuracy'])

from keras.callbacks import TensorBoard
# Use TensorBoard
callbacks = TensorBoard(log_dir='./Graph')

from keras.preprocessing.image import ImageDataGenerator

train_datagen = ImageDataGenerator(rescale = 1./255,
                                   shear_range = 0.2,
                                   zoom_range = 0.2,
                                   horizontal_flip = True)

test_datagen = ImageDataGenerator(rescale = 1./255)

training_set = train_datagen.flow_from_directory('dataset/training_set',
                                                 target_size = (64, 64),
                                                 batch_size = 32,
                                                 class_mode = 'binary')

test_set = test_datagen.flow_from_directory('dataset/test_set',
                                            target_size = (64, 64),
                                            batch_size = 32,
                                            class_mode = 'binary')

classifier.fit_generator(training_set,
                         steps_per_epoch = 100,
                         epochs = 200,
                         validation_data = test_set,
                         validation_steps = 200)

classifier.save('model.h5')

我得到了这个结果(对不起,我不知道如何把图像放在这里)

纪元 198/200 100/100 [===============================] - 114s 1s/step - loss: 0.1032 - acc :0.9619 - val_loss:1.1953 - val_acc:0.7160

纪元 199/200 100/100 [===============================] - 115s 1s/步 - 损失:0.1107 - acc :0.9591 - val_loss:1.4148 - val_acc:0.6702

纪元 200/200 100/100 [===============================] - 112s 1s/步 - 损失:0.1229 - acc :0.9528 - val_loss:1.2995 - val_acc:0.6928

标签: pythondeep-learningconv-neural-network

解决方案


当你的训练准确度很高,但验证准确度很低时,你的模型就过拟合了。简单地说,您的模型已经了解了训练数据的结构,但无法对其进行概括。为了减少过拟合,可以尝试

  • 简化你的模型,
  • dropout引入某些层,
  • 使用更大的训练批次。

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