我正在遵循Rajsha做的指南:https://github.com/rajshah4/image_keras/blob/master/notebook_extras.ipynb
这个想法是将VGG16应用于我的数据集,它由spectogram组成,并让它在两个类之间做出决定,正常和异常。
然而,模型没有学习,尽管我在顶层,但我得到了大约0.5 val_acc。
我做错了什么吗?我将把我的代码留在下面:
# dimensions of our images
img_width, img_height = 240, 240
train_data_dir = '/content/gdrive/My Drive/Melspec/melspecimages/train'
validation_data_dir = '/content/gdrive/My Drive/Melspec/melspecimages/val'
batch_size = 32
datagen = ImageDataGenerator(preprocessing_function=preprocess_input)
model_vgg = applications.VGG16(include_top=False, weights='imagenet',input_shape=(240,240,3))
model_vgg.trainable=False
train_generator_bottleneck = datagen.flow_from_directory(
train_data_dir,
target_size=(img_width, img_height),
batch_size=batch_size,
class_mode='binary',
shuffle=True)
validation_generator_bottleneck = datagen.flow_from_directory(
validation_data_dir,
target_size=(img_width, img_height),
batch_size=batch_size,
class_mode='binary',
shuffle=False)
train_samples = 30272
validation_samples = 7584
bottleneck_features_train = model_vgg.predict_generator(train_generator_bottleneck, train_samples // batch_size)
np.save(open('/content/gdrive/My Drive/Melspec/spec_vgg_bottleneck_features_train.npy', 'wb'), bottleneck_features_train)
bottleneck_features_validation = model_vgg.predict_generator(validation_generator_bottleneck, validation_samples // batch_size)
np.save(open('/content/gdrive/My Drive/Melspec/spec_vgg_bottleneck_features_validation.npy', 'wb'), bottleneck_features_validation)
train_data = np.load(open('/content/gdrive/My Drive/Melspec/spec_vgg_bottleneck_features_train.npy', 'rb'))
train_labels = np.array([0] * (train_samples // 2) + [1] * (train_samples // 2))
validation_data = np.load(open('/content/gdrive/My Drive/Melspec/spec_vgg_bottleneck_features_validation.npy', 'rb'))
validation_labels = np.array([0] * (validation_samples // 2) + [1] * (validation_samples // 2))
model_top = Sequential()
model_top.add(Flatten(input_shape=train_data.shape[1:]))
model_top.add(Dense(256, activation='relu'))
model_top.add(Dropout(0.5))
model_top.add(Dense(1, activation='sigmoid'))
model_top.compile(optimizer='rmsprop', loss='binary_crossentropy', metrics=['accuracy'])
model_top.fit(train_data, train_labels,
epochs=epochs,
batch_size=batch_size,
validation_data=(validation_data, validation_labels))发布于 2019-11-22 02:45:54
找到了答案:我的标签错了。
我在网上读到,我们应该在提供train_generator时使用shuffle=True,但是类没有以相同的顺序混合,只有文件,因此导致了错误的标签。
我切换到了shuffle=False和class_mode=None。
我还必须确保我的数据库中的文件在两个类中具有相同的编号,并且这些文件可以被我的batch_size整除。
希望这对其他初学者有所帮助!
https://stackoverflow.com/questions/58966160
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