这篇文章是使用tensorflow_hub,进行图像分类的指南,原文在这里.
环境搭建
import itertools
import os
import matplotlib.pylab as plt
import numpy as np
import tensorflow as tf
import tensorflow_hub as hub
print("TF version:", tf.__version__)
print("Hub version:", hub.__version__)
print("GPU is", "available" if tf.test.is_gpu_available() else "NOT AVAILABLE")
TF version: 2.2.0
Hub version: 0.8.0
WARNING:tensorflow:From :12: is_gpu_available (from tensorflow.python.framework.test_util) is deprecated and will be removed in a future version.
Instructions for updating:
Use `tf.config.list_physical_devices('GPU')` instead.
GPU is available
下载预处理模型
module_selection = ("mobilenet_v2_100_224", 224)
handle_base, pixels = module_selection
MODULE_HANDLE ="https://tfhub.dev/google/imagenet/{}/feature_vector/4".format(handle_base)
IMAGE_SIZE = (pixels, pixels)
print("Using {} with input size {}".format(MODULE_HANDLE, IMAGE_SIZE))
BATCH_SIZE = 32
Using https://tfhub.dev/google/imagenet/mobilenet_v2_100_224/feature_vector/4 with input size (224, 224)
设置鲜花数据集
data_dir = tf.keras.utils.get_file(
'flower_photos',
'https://storage.googleapis.com/download.tensorflow.org/example_images/flower_photos.tgz',
untar=True)
Downloading data from https://storage.googleapis.com/download.tensorflow.org/example_images/flower_photos.tgz
228818944/228813984 [==============================] - 4s 0us/step
datagen_kwargs = dict(rescale=1./255, validation_split=.20)
dataflow_kwargs = dict(target_size=IMAGE_SIZE, batch_size=BATCH_SIZE,
interpolation="bilinear")
valid_datagen = tf.keras.preprocessing.image.ImageDataGenerator(
**datagen_kwargs)
valid_generator = valid_datagen.flow_from_directory(
data_dir, subset="validation", shuffle=False, **dataflow_kwargs)
do_data_augmentation = False
if do_data_augmentation:
train_datagen = tf.keras.preprocessing.image.ImageDataGenerator(
rotation_range=40,
horizontal_flip=True,
width_shift_range=0.2, height_shift_range=0.2,
shear_range=0.2, zoom_range=0.2,
**datagen_kwargs)
else:
train_datagen = valid_datagen
train_generator = train_datagen.flow_from_directory(
data_dir, subset="training", shuffle=True, **dataflow_kwargs)
Found 731 images belonging to 5 classes.
Found 2939 images belonging to 5 classes.
do_fine_tuning = False
print("Building model with", MODULE_HANDLE)
model = tf.keras.Sequential([
# Explicitly define the input shape so the model can be properly
# loaded by the TFLiteConverter
tf.keras.layers.InputLayer(input_shape=IMAGE_SIZE + (3,)),
hub.KerasLayer(MODULE_HANDLE, trainable=do_fine_tuning),
tf.keras.layers.Dropout(rate=0.2),
tf.keras.layers.Dense(train_generator.num_classes,
kernel_regularizer=tf.keras.regularizers.l2(0.0001))
])
model.build((None,)+IMAGE_SIZE+(3,))
model.summary()
Building model with https://tfhub.dev/google/imagenet/mobilenet_v2_100_224/feature_vector/4
Model: "sequential"
_________________________________________________________________
Layer (type) Output Shape Param #
=================================================================
keras_layer (KerasLayer) (None, 1280) 2257984
_________________________________________________________________
dropout (Dropout) (None, 1280) 0
_________________________________________________________________
dense (Dense) (None, 5) 6405
=================================================================
Total params: 2,264,389
Trainable params: 6,405
Non-trainable params: 2,257,984
_________________________________________________________________
model.compile(
optimizer=tf.keras.optimizers.SGD(lr=0.005, momentum=0.9),
loss=tf.keras.losses.CategoricalCrossentropy(from_logits=True, label_smoothing=0.1),
metrics=['accuracy'])
steps_per_epoch = train_generator.samples // train_generator.batch_size
validation_steps = valid_generator.samples // valid_generator.batch_size
hist = model.fit(
train_generator,
epochs=5, steps_per_epoch=steps_per_epoch,
validation_data=valid_generator,
validation_steps=validation_steps).history
Epoch 1/5
91/91 [==============================] - 15s 165ms/step - loss: 0.9333 - accuracy: 0.7544 - val_loss: 0.7685 - val_accuracy: 0.8239
Epoch 2/5
91/91 [==============================] - 14s 158ms/step - loss: 0.7039 - accuracy: 0.8720 - val_loss: 0.7094 - val_accuracy: 0.8537
Epoch 3/5
91/91 [==============================] - 14s 157ms/step - loss: 0.6443 - accuracy: 0.9023 - val_loss: 0.7079 - val_accuracy: 0.8565
Epoch 4/5
91/91 [==============================] - 14s 158ms/step - loss: 0.6212 - accuracy: 0.9168 - val_loss: 0.7030 - val_accuracy: 0.8537
Epoch 5/5
91/91 [==============================] - 14s 156ms/step - loss: 0.6051 - accuracy: 0.9278 - val_loss: 0.6684 - val_accuracy: 0.8864
plt.figure()
plt.ylabel("Loss (training and validation)")
plt.xlabel("Training Steps")
plt.ylim([0,2])
plt.plot(hist["loss"])
plt.plot(hist["val_loss"])
plt.figure()
plt.ylabel("Accuracy (training and validation)")
plt.xlabel("Training Steps")
plt.ylim([0,1])
plt.plot(hist["accuracy"])
plt.plot(hist["val_accuracy"])
保存模型
saved_model_path = "/tmp/saved_flowers_model"
tf.saved_model.save(model, saved_model_path)
WARNING:tensorflow:From /tmpfs/src/tf_docs_env/lib/python3.6/site-packages/tensorflow/python/ops/resource_variable_ops.py:1817: calling BaseResourceVariable.__init__ (from tensorflow.python.ops.resource_variable_ops) with constraint is deprecated and will be removed in a future version.
Instructions for updating:
If using Keras pass *_constraint arguments to layers.
Warning:tensorflow:From /tmpfs/src/tf_docs_env/lib/python3.6/site-packages/tensorflow/python/ops/resource_variable_ops.py:1817: calling BaseResourceVariable.__init__ (from tensorflow.python.ops.resource_variable_ops) with constraint is deprecated and will be removed in a future version.
Instructions for updating:
If using Keras pass *_constraint arguments to layers.
INFO:tensorflow:Assets written to: /tmp/saved_flowers_model/assets
INFO:tensorflow:Assets written to: /tmp/saved_flowers_model/assets
TensorFlow Lite可让您将TensorFlow模型部署到移动和IoT设备。以下代码显示了如何将训练后的模型转换为TF Lite并应用TensorFlow Model Optimization Toolkit中的后训练工具。最后,它在TF Lite解释器中运行以检查最终的质量
# TODO(b/156102192)
optimize_lite_model = False
num_calibration_examples = 60
representative_dataset = None
if optimize_lite_model and num_calibration_examples:
# Use a bounded number of training examples without labels for calibration.
# TFLiteConverter expects a list of input tensors, each with batch size 1.
representative_dataset = lambda: itertools.islice(
([image[None, ...]] for batch, _ in train_generator for image in batch),
num_calibration_examples)
converter = tf.lite.TFLiteConverter.from_saved_model(saved_model_path)
if optimize_lite_model:
converter.optimizations = [tf.lite.Optimize.DEFAULT]
if representative_dataset: # This is optional, see above.
converter.representative_dataset = representative_dataset
lite_model_content = converter.convert()
with open("/tmp/lite_flowers_model", "wb") as f:
f.write(lite_model_content)
print("Wrote %sTFLite model of %d bytes." %
("optimized " if optimize_lite_model else "", len(lite_model_content)))
interpreter = tf.lite.Interpreter(model_content=lite_model_content)
# This little helper wraps the TF Lite interpreter as a numpy-to-numpy function.
def lite_model(images):
interpreter.allocate_tensors()
interpreter.set_tensor(interpreter.get_input_details()[0]['index'], images)
interpreter.invoke()
return interpreter.get_tensor(interpreter.get_output_details()[0]['index'])
num_eval_examples = 50
eval_dataset = ((image, label) # TFLite expects batch size 1.
for batch in train_generator
for (image, label) in zip(*batch))
count = 0
count_lite_tf_agree = 0
count_lite_correct = 0
for image, label in eval_dataset:
probs_lite = lite_model(image[None, ...])[0]
probs_tf = model(image[None, ...]).numpy()[0]
y_lite = np.argmax(probs_lite)
y_tf = np.argmax(probs_tf)
y_true = np.argmax(label)
count +=1
if y_lite == y_tf: count_lite_tf_agree += 1
if y_lite == y_true: count_lite_correct += 1
if count >= num_eval_examples: break
print("TF Lite model agrees with original model on %d of %d examples (%g%%)." %
(count_lite_tf_agree, count, 100.0 * count_lite_tf_agree / count))
print("TF Lite model is accurate on %d of %d examples (%g%%)." %
(count_lite_correct, count, 100.0 * count_lite_correct / count))
最后的话:
这篇文章发布在CSDN/蓝色的杯子, 没事多留言,让我们一起爱智求真吧.我的邮箱[email protected].