我目前正在尝试使用具有 2 个类的 Inception V3 创建一个图像分类模型。我有 1428 张图像,它们的平衡度约为 70/30。当我运行我的模型时,我得到了相当高的损失以及恒定的验证准确性。什么可能导致这个恒定值?
data = np.array(data, dtype="float")/255.0
labels = np.array(labels,dtype ="uint8")
(trainX, testX, trainY, testY) = train_test_split(
data,labels,
test_size=0.2,
random_state=42)
img_width, img_height = 320, 320 #InceptionV3 size
train_samples = 1145
validation_samples = 287
epochs = 20
batch_size = 32
base_model = keras.applications.InceptionV3(
weights ='imagenet',
include_top=False,
input_shape = (img_width,img_height,3))
model_top = keras.models.Sequential()
model_top.add(keras.layers.GlobalAveragePooling2D(input_shape=base_model.output_shape[1:], data_format=None)),
model_top.add(keras.layers.Dense(350,activation='relu'))
model_top.add(keras.layers.Dropout(0.2))
model_top.add(keras.layers.Dense(1,activation = 'sigmoid'))
model = keras.models.Model(inputs = base_model.input, outputs = model_top(base_model.output))
for layer in model.layers[:30]:
layer.trainable = False
model.compile(optimizer = keras.optimizers.Adam(
lr=0.00001,
beta_1=0.9,
beta_2=0.999,
epsilon=1e-08),
loss='binary_crossentropy',
metrics=['accuracy'])
#Image Processing and Augmentation
train_datagen = keras.preprocessing.image.ImageDataGenerator(
zoom_range = 0.05,
#width_shift_range = 0.05,
height_shift_range = 0.05,
horizontal_flip = True,
vertical_flip = True,
fill_mode ='nearest')
val_datagen = keras.preprocessing.image.ImageDataGenerator()
train_generator = train_datagen.flow(
trainX,
trainY,
batch_size=batch_size,
shuffle=True)
validation_generator = val_datagen.flow(
testX,
testY,
batch_size=batch_size)
history = model.fit_generator(
train_generator,
steps_per_epoch = train_samples//batch_size,
epochs = epochs,
validation_data = validation_generator,
validation_steps = validation_samples//batch_size,
callbacks = [ModelCheckpoint])
这是我运行模型时的日志:
Epoch 1/20
35/35 [==============================]35/35[==============================] - 52s 1s/step - loss: 0.6347 - acc: 0.6830 - val_loss: 0.6237 - val_acc: 0.6875
Epoch 2/20
35/35 [==============================]35/35 [==============================] - 14s 411ms/step - loss: 0.6364 - acc: 0.6756 - val_loss: 0.6265 - val_acc: 0.6875
Epoch 3/20
35/35 [==============================]35/35 [==============================] - 14s 411ms/step - loss: 0.6420 - acc: 0.6743 - val_loss: 0.6254 - val_acc: 0.6875
Epoch 4/20
35/35 [==============================]35/35 [==============================] - 14s 414ms/step - loss: 0.6365 - acc: 0.6851 - val_loss: 0.6289 - val_acc: 0.6875
Epoch 5/20
35/35 [==============================]35/35 [==============================] - 14s 411ms/step - loss: 0.6359 - acc: 0.6727 - val_loss: 0.6244 - val_acc: 0.6875
Epoch 6/20
35/35 [==============================]35/35 [==============================] - 15s 415ms/step - loss: 0.6342 - acc: 0.6862 - val_loss: 0.6243 - val_acc: 0.6875
最佳答案
我认为你的学习率太低,时代太少。尝试使用 lr = 0.001
和 epochs = 100
。
关于python - 机器学习中具有高损失的恒定验证精度,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/52598959/