1.背景を使用する
微調整にケラを使用する場合、トレーニングを加速するために一部のネットワーク層をフリーズする必要がある場合があります
kerasの単一のレイヤーをフリーズする方法があります:layer.trainable = False
2.モデルのすべてのネットワーク層をフリーズします
base_model = DenseNet121(include_top=False, weights="imagenet", input_shape=(224, 224, 3))
for layer in base_model.layers:
layer.trainable = False
3、モデルのいくつかのネットワーク層をフリーズします
ケラスでは、model.layersからレイヤーを取得するだけでなく、model.get_layer(layer_name)からも取得できます。
base_model = VGG19(weights='imagenet')
base_model.get_layer('block4_pool').trainable = False
layer_nameを知る方法は?
答えは、
以下に示すようにmodel.summary()を介して出力することです。左端の列はlayer_nameです(括弧の外側にあることに注意してください)。
__________________________________________________________________________________________________
Layer (type) Output Shape Param # Connected to
==================================================================================================
input_1 (InputLayer) (None, 224, 224, 3) 0
__________________________________________________________________________________________________
NASNet (Model) (None, 7, 7, 1056) 4269716 input_1[0][0]
__________________________________________________________________________________________________
resnet50 (Model) (None, 7, 7, 2048) 23587712 input_1[0][0]
__________________________________________________________________________________________________
densenet121 (Model) (None, 7, 7, 1024) 7037504 input_1[0][0]
__________________________________________________________________________________________________
global_average_pooling2d_1 (Glo (None, 1056) 0 NASNet[1][0]
__________________________________________________________________________________________________
global_average_pooling2d_2 (Glo (None, 2048) 0 resnet50[1][0]
__________________________________________________________________________________________________
global_average_pooling2d_3 (Glo (None, 1024) 0 densenet121[1][0]
__________________________________________________________________________________________________
concatenate_5 (Concatenate) (None, 4128) 0 global_average_pooling2d_1[0][0]
global_average_pooling2d_2[0][0]
global_average_pooling2d_3[0][0]
__________________________________________________________________________________________________
dropout_1 (Dropout) (None, 4128) 0 concatenate_5[0][0]
__________________________________________________________________________________________________
classifier (Dense) (None, 200) 825800 dropout_1[0][0]
==================================================================================================
Total params: 35,720,732
Trainable params: 825,800
Non-trainable params: 34,894,932
__________________________________________________________________________________________________
None