+
+
+
+
+
+
+In [1]:
+
+
+
+
+
+# import libraries
+import numpy as np
+import tensorflow as tf
+import keras_tuner
+import PIL
+import matplotlib.pyplot as plt
+import pandas as pd
+
+# Seed the tf, numpy and python with a fix random number
+seed = 93
+import random # from the python library
+random.seed(seed)
+np.random.seed(seed)
+tf.random.set_seed(seed)
+
+# Set the difficulty level to train
+DIFF_LEVEL = "binary" # binary, multi, easy, mid, hard
+
+# Train all the images with binary label
+NUM_CLASSES = 1 # number of classes = 5 if multilabel is used
+
+
+
+
+
+
+
+In [2]:
+
+
+
+
+
+# List the gpu
+devices = tf.config.list_physical_devices("GPU")
+print(devices)
+
+
+
+
+
+
+
+
+
+
+
+[PhysicalDevice(name='/physical_device:GPU:0', device_type='GPU')] ++
+
+
+
+
+
+
+In [3]:
+
+
+
+
+
+# path of the dataset saved from previous step
+import os
+# path: dataset\train\ds_binary.
+# path: dataset\train\ds_multi.
+diff_level = f"ds_{DIFF_LEVEL}"
+dataset_file = os.path.join("dataset", "train", diff_level)
+print(f"Dataset file: {dataset_file}")
+if os.path.exists(dataset_file) is False:
+ print(f"File not found: {dataset_file}")
+ exit(0)
+# Load the dataset
+ds = tf.data.Dataset.load(dataset_file)
+
+
+
+
+
+
+
+
+
+
+
+Dataset file: dataset\train\ds_binary ++
+
+
+
+
+
+
+In [4]:
+
+
+
+
+
+# print the loaded dataset info
+def print_dataset_info(dataset):
+ print(f"Image arrays: {dataset.element_spec[0].shape}, {dataset.element_spec[0].dtype}")
+ print(f"Label arrays: {dataset.element_spec[1].shape}, {dataset.element_spec[1].dtype}")
+ print(f"cardinality: {dataset.cardinality()}")
+
+
+
+
+
+
+
+
+In [5]:
+
+
+
+
+
+print_dataset_info(ds)
+
+
+
+
+
+
+
+
+
+
+
+Image arrays: (224, 224, 3), <dtype: 'float32'> +Label arrays: (), <dtype: 'int32'> +cardinality: 2028 ++
+
+
+
+
+
+
+
+
+Prepare dataset¶
+
+
+
+
+
+
+
+In [6]:
+
+
+
+
+
+# split the dataset into train and validation set
+ds_train, ds_val = tf.keras.utils.split_dataset(
+ ds, left_size=0.9, right_size=0.1, shuffle=True, seed=seed
+)
+
+
+
+
+
+
+
+In [7]:
+
+
+
+
+
+print(f"train set: {ds_train.cardinality()}, \nvalidation set: {ds_val.cardinality()}")
+
+
+
+
+
+
+
+
+
+
+
+train set: 1825, +validation set: 203 ++
+
+
+
+
+
+
+In [8]:
+
+
+
+
+
+# preprocess input
+# data augmentation and the pretrained model's preprocess function
+img_augmentation_layers = [
+ tf.keras.layers.RandomRotation(factor=0.15),
+ tf.keras.layers.RandomTranslation(height_factor=0.1, width_factor=0.1),
+]
+
+def img_augmentation(images):
+ for layer in img_augmentation_layers:
+ images = layer(images)
+ return images
+
+# the preprocess function of the pretrained model
+pretrained_model_preprocess_fn = tf.keras.applications.efficientnet_v2.preprocess_input
+
+def input_preprocess_train(image, label):
+ #image = img_augmentation(image)
+ image = pretrained_model_preprocess_fn(image)
+ return image, label
+
+# do not augment the data in the validation or test set
+def input_preprocess_test(image, label):
+ image = pretrained_model_preprocess_fn(image)
+ return image, label
+
+
+
+
+
+
+
+In [9]:
+
+
+
+
+
+BATCH_SIZE = 16
+
+ds_train = ds_train.shuffle(buffer_size=1000, seed=seed)
+ds_train = ds_train.map(lambda x, y: input_preprocess_train(x, y),
+ num_parallel_calls=tf.data.AUTOTUNE,
+ deterministic=True)
+ds_train = ds_train.cache()
+ds_train = ds_train.batch(batch_size=BATCH_SIZE,
+ num_parallel_calls=tf.data.AUTOTUNE,
+ deterministic=True,
+ drop_remainder=True)
+ds_train = ds_train.prefetch(tf.data.AUTOTUNE)
+
+
+
+
+
+
+
+In [10]:
+
+
+
+
+
+ds_val = ds_val.shuffle(buffer_size=1000, seed=seed)
+ds_val = ds_val.map(lambda x, y: input_preprocess_test(x, y),
+ num_parallel_calls=tf.data.AUTOTUNE,
+ deterministic=True)
+ds_val = ds_val.cache()
+ds_val = ds_val.batch(batch_size=BATCH_SIZE,
+ num_parallel_calls=tf.data.AUTOTUNE,
+ deterministic=True,
+ drop_remainder=True)
+ds_val = ds_val.prefetch(tf.data.AUTOTUNE)
+
+
+
+
+
+
+
+In [11]:
+
+
+
+
+
+ds_t = ds_train.take(1)
+ds_v = ds_val.take(1)
+
+
+
+
+
+
+
+In [12]:
+
+
+
+
+
+ds_t
+
+
+
+
+
+
+
+
+Out[12]:
+
+
+<TakeDataset element_spec=(TensorSpec(shape=(16, 224, 224, 3), dtype=tf.float32, name=None), TensorSpec(shape=(16,), dtype=tf.int32, name=None))>+
+
+
+
+
+
+
+In [13]:
+
+
+
+
+
+ds_v
+
+
+
+
+
+
+
+
+Out[13]:
+
+
+<TakeDataset element_spec=(TensorSpec(shape=(16, 224, 224, 3), dtype=tf.float32, name=None), TensorSpec(shape=(16,), dtype=tf.int32, name=None))>+
+
+
+
+
+
+
+
+In [14]:
+
+
+
+
+
+print(f"train set: {ds_t.cardinality()}, \nvalidation set: {ds_v.cardinality()}")
+
+
+
+
+
+
+
+
+
+
+
+train set: 1, +validation set: 1 ++
+
+
+
+
+
+
+
+
+Callbacks layers and optimizer learning rate scheduler¶
+
+
+
+
+
+
+
+
+In [15]:
+
+
+
+
+
+# The ModelCheckpoint callback can be used to implement fault-tolerance: the
+# ability to restart training from the last saved state of the model in case
+# training gets randomly interrupted.
+# setup the callbacks
+# tensorboard log directory
+logdir = "logdir"
+checkpoint_dir = "checkpoint"
+
+# check for the directory
+if not os.path.exists(logdir):
+ os.mkdir(logdir)
+if not os.path.exists(checkpoint_dir):
+ os.mkdir(checkpoint_dir)
+
+import time # to format time
+model_name = f"best_{DIFF_LEVEL}_{time.strftime('%d_%m_%H%M')}.keras"
+checkpoint_filepath = os.path.join(checkpoint_dir, model_name)
+print(f"Checkpoint filepath: {checkpoint_filepath}")
+callbacks = [
+ # early stopping
+ tf.keras.callbacks.EarlyStopping(patience=150),
+ # Save the best model
+ tf.keras.callbacks.ModelCheckpoint(
+ filepath=checkpoint_filepath,
+ save_weights_only=True,
+ monitor='val_binary_accuracy',
+ mode='max',
+ save_best_only=True
+ ),
+ # tensorboard
+ tf.keras.callbacks.TensorBoard(
+ log_dir=logdir,
+ update_freq="epoch"
+ )
+]
+
+
+
+
+
+
+
+
+
+
+
+Checkpoint filepath: checkpoint\best_binary_10_02_1124.keras ++
+
+
+
+
+
+
+
+
+Learning rate scheduluer¶
+
+
+
+
+
+
+
+In [16]:
+
+
+
+
+
+# Not using
+# Gradually reduce learning rate
+# Use default value
+
+initial_learning_rate = 1e-3
+lr_schedule = tf.keras.optimizers.schedules.ExponentialDecay(
+ initial_learning_rate,
+ decay_steps=100000,
+ decay_rate=0.96,
+ staircase=True
+)
+
+lr_schedule
+
+
+
+
+
+
+
+
+Out[16]:
+
+
+<keras.optimizers.schedules.learning_rate_schedule.ExponentialDecay at 0x21ab1367340>+
+
+
+
+
+
+
+
+In [ ]:
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Efficient net¶
+
+
+
+
+
+
+
+In [17]:
+
+
+
+
+
+# prepare the dataset
+def plot_history(history):
+ plt.plot(history.history["binary_accuracy"])
+ plt.plot(history.history["val_binary_accuracy"])
+ plt.title("Model accuracy")
+ plt.ylabel("accuracy")
+ plt.xlabel("epoch")
+ plt.grid(visible=True, axis="both")
+ plt.legend(["train", "validation"], loc="upper left")
+ plt.show()
+
+
+
+
+
+
+
+
+In [18]:
+
+
+
+
+
+# EfficientNetB7, image resolution: 600 x 600
+
+# Get the image size
+IMG_SIZE = ds.element_spec[0].shape[1]
+print(f"Image size: {IMG_SIZE}")
+
+
+
+
+
+
+
+
+
+
+
+Image size: 224 ++
+
+
+
+
+
+
+
+In [19]:
+
+
+
+
+
+# EfficientNetV2 models expect their inputs to be float tensors of pixels with values in the [0-255] range.
+# Use EfficientNetB7
+
+# build_model: Set the range of hyperparameters.
+# Then, it will call the exisiting model building code.
+def build_model(hp):
+ pooling = hp.Choice("pooling", ["average", "global"])
+ norm = hp.Boolean("norm")
+ units = hp.Int("units", min_value=64, max_value=512, step=32)
+ dropout = hp.Float("dropout", min_value=0.1, max_value=0.4, step=0.1)
+ # call the actual model building code
+ model = call_existing_code(pooling, norm, units, dropout)
+ return model
+
+# This is called by the keras tuner.
+# This is the existing model building code that is working.
+def call_existing_code(pooling, norm, units, dropout):
+ inputs = tf.keras.layers.Input(shape=(IMG_SIZE, IMG_SIZE, 3))
+ # drop_connect_rate which controls the dropout rate responsible for stochastic depth
+ # use this for stronger regularization
+ global base_model
+ base_model = tf.keras.applications.EfficientNetV2B0(
+ include_top=False,
+ input_tensor=inputs,
+ weights="imagenet",
+ )
+
+ # Freeze the pretrained weights
+ base_model.trainable = False
+
+ # Rebuild top
+ # pooling=None means that the output of the model will be the
+ # 4D tensor output of the last convolutional layer.
+ if pooling == "average":
+ x = tf.keras.layers.GlobalAveragePooling2D(name="avg_pool")(base_model.output)
+ elif pooling == "global":
+ x = tf.keras.layers.GlobalMaxPooling2D(name="max_pool")(base_model.output)
+
+ # if normalization is used
+ if norm is True:
+ x = tf.keras.layers.BatchNormalization()(x)
+
+ # Add a dense layer
+ # The units are chosen from the hyperparameters
+ x = tf.keras.layers.Dense(units, activation='relu')(x)
+ # Drop out
+ # dropout rate from the hyperparameters
+ top_dropout_rate = dropout
+ x = tf.keras.layers.Dropout(
+ top_dropout_rate,
+ name="top_dropout",
+ seed=seed
+ )(x)
+ # set the number of classes
+ num_classes = NUM_CLASSES
+ outputs = tf.keras.layers.Dense(
+ num_classes,
+ activation="sigmoid",
+ name="predict",
+ kernel_regularizer="l2",
+ bias_regularizer="l2",
+ activity_regularizer="l2",
+ )(x)
+
+ model = tf.keras.Model(inputs, outputs, name="MyEfficient-V2B0")
+ model = compile_model(model)
+ return model
+
+def compile_model(model):
+ # Compile
+ optimizer = tf.keras.optimizers.Adam(learning_rate=lr_schedule)
+ metrics = [
+ tf.keras.metrics.BinaryAccuracy(),
+ tf.keras.metrics.Precision(name="precision"),
+ tf.keras.metrics.Recall(name="recall"),
+ ]
+ model.compile(
+ optimizer=optimizer,
+ loss="binary_crossentropy",
+ metrics=metrics,
+ )
+
+ return model
+
+
+
+
+
+
+
+
+
+Keras tuner searche_summary()¶
+
+
+
+
+
+
+
+In [20]:
+
+
+
+
+
+tuner = keras_tuner.RandomSearch(
+ hypermodel=build_model,
+ objective="val_binary_accuracy",
+ max_trials=10,
+ executions_per_trial=2,
+ seed=seed,
+ overwrite=True,
+ directory="hp_search",
+ project_name="all_faces",
+)
+
+tuner.search_space_summary()
+
+
+
+
+
+
+
+
+
+
+
+Search space summary
+Default search space size: 4
+pooling (Choice)
+{'default': 'average', 'conditions': [], 'values': ['average', 'global'], 'ordered': False}
+norm (Boolean)
+{'default': False, 'conditions': []}
+units (Int)
+{'default': None, 'conditions': [], 'min_value': 64, 'max_value': 512, 'step': 32, 'sampling': 'linear'}
+dropout (Float)
+{'default': 0.1, 'conditions': [], 'min_value': 0.1, 'max_value': 0.4, 'step': 0.1, 'sampling': 'linear'}
+
+
+
+
+
+
+
+
+In [21]:
+
+
+
+
+
+model = build_model(keras_tuner.HyperParameters())
+#model = compile_model(model) # this will be called in the build_model
+
+epochs = 1000
+
+
+
+
+
+
+
+In [22]:
+
+
+
+
+
+# This will be called by the tuner search
+tuner.search(ds_train, epochs=epochs, validation_data=ds_val, callbacks=callbacks)
+
+
+
+
+
+
+
+
+
+
+
+Trial 10 Complete [01h 26m 10s] +val_binary_accuracy: 0.6197916865348816 + +Best val_binary_accuracy So Far: 0.6770833730697632 +Total elapsed time: 18h 22m 19s ++
+
+
+
+
+
+
+In [23]:
+
+
+
+
+
+# The model weights (that are considered the best) can be loaded as -
+#model.load_weights(checkpoint_filepath)
+model_list = tuner.get_best_models(num_models=1)
+model = model_list[0] # the best model from the tuner
+# print a summary of the best trials
+tuner.results_summary(num_trials=1)
+
+
+
+
+
+
+
+
+
+
+
+Results summary +Results in hp_search\all_faces +Showing 1 best trials +Objective(name="val_binary_accuracy", direction="max") + +Trial 02 summary +Hyperparameters: +pooling: global +norm: False +units: 512 +dropout: 0.4 +Score: 0.6770833730697632 ++
+
+
+
+
+
+
+In [35]:
+
+
+
+
+
+# Save the best model
+best_model = model_list[0] # the best model from the tuner
+
+
+
+
+
+
+
+In [34]:
+
+
+
+
+
+# print a summary of a few moretrials
+tuner.results_summary(num_trials=5)
+
+
+
+
+
+
+
+
+
+
+
+Results summary +Results in hp_search\all_faces +Showing 5 best trials +Objective(name="val_binary_accuracy", direction="max") + +Trial 02 summary +Hyperparameters: +pooling: global +norm: False +units: 512 +dropout: 0.4 +Score: 0.6770833730697632 + +Trial 08 summary +Hyperparameters: +pooling: global +norm: True +units: 64 +dropout: 0.4 +Score: 0.6588541865348816 + +Trial 07 summary +Hyperparameters: +pooling: average +norm: True +units: 64 +dropout: 0.4 +Score: 0.65625 + +Trial 05 summary +Hyperparameters: +pooling: average +norm: False +units: 480 +dropout: 0.4 +Score: 0.6536458432674408 + +Trial 01 summary +Hyperparameters: +pooling: average +norm: False +units: 256 +dropout: 0.1 +Score: 0.6484375298023224 ++
+
+
+
+
+
+
+
+In [25]:
+
+
+
+
+
+# Reference: https://keras.io/api/applications/
+
+# Layers in the base models and models
+print(f"Number of layers in base model {base_model.name}: {len(base_model.layers)}")
+print(f"Number of layers in feature extraction model {model.name}: {len(model.layers)}")
+
+
+
+
+
+
+
+
+
+
+
+Number of layers in base model efficientnetv2-b0: 270 +Number of layers in feature extraction model MyEfficient-V2B0: 274 ++
+
+
+
+
+
+
+
+
+Further layer unfreezing is not workable on my device.
+
+
+
+
+
+
+
+In [26]:
+
+
+
+
+
+# we chose to train the top 1 we will freeze
+# the first 249 layers and unfreeze the rest:
+#
+"""
+for layer in model.layers[:268]:
+ layer.trainable = False
+for layer in model.layers[268:]:
+ layer.trainable = True
+"""
+
+
+
+
+
+
+
+
+Out[26]:
+
+
+'\nfor layer in model.layers[:268]:\n layer.trainable = False\nfor layer in model.layers[268:]:\n layer.trainable = True\n'+
+
+
+
+
+
+
+
+In [27]:
+
+
+
+
+
+"""
+model = compile_model(model)
+model.fit(ds_train,
+ epochs=epochs,
+ validation_data=ds_val,
+ callbacks=callbacks)
+"""
+
+
+
+
+
+
+
+
+Out[27]:
+
+
+'\nmodel = compile_model(model)\nmodel.fit(ds_train,\n epochs=epochs, \n validation_data=ds_val,\n callbacks=callbacks)\n'+
+
+
+
+
+
+
+
+
+Save the model¶
+
+
+
+
+
+
+
+In [37]:
+
+
+
+
+
+# Save in tf SavedModel format
+model_filepath = os.path.join("model", "all_binary_tf_6771")
+tf.saved_model.save(best_model, model_filepath)
+
+
+
+
+
+
+
+
+
+
+
+WARNING:absl:Found untraced functions such as _jit_compiled_convolution_op, _jit_compiled_convolution_op, _jit_compiled_convolution_op, _jit_compiled_convolution_op, _jit_compiled_convolution_op while saving (showing 5 of 91). These functions will not be directly callable after loading. ++
+
+
+
+
+INFO:tensorflow:Assets written to: model\all_binary_tf_6771\assets ++
+
+
+
+
+INFO:tensorflow:Assets written to: model\all_binary_tf_6771\assets ++
+
+
+
+
+
+
+
+In [38]:
+
+
+
+
+
+# save in keras format
+model_filepath = os.path.join("model", "all_binary_6771.keras")
+tf.keras.models.save_model(best_model, model_filepath, overwrite=True)
+
+
+
+
+
+
+
+
+
+What would happened if the best hyperparameters are used to retrained the model?¶
Retrained the model with the best hyperparameters. However the val_binary_accuracy was not the same as the one from the best model. The reason could be that one epoch is not enough. The retraining may need many epochs to reach the val_binary_accuracy like the best model.
+
+
+
+
+
+
+
+In [24]:
+
+
+
+
+
+# Get the top hyperparameters.
+best_hps = tuner.get_best_hyperparameters(1)
+# Build the model with the best hp.
+model = build_model(best_hps[0])
+# Fit with the entire dataset.
+# Only need to train 1 time with the best hyperparameters.
+history = model.fit(ds_train, epochs=1, validation_data=ds_val, callbacks=callbacks)
+
+
+
+
+
+
+
+
+
+
+
+114/114 [==============================] - 21s 152ms/step - loss: 1.7248 - binary_accuracy: 0.5132 - precision: 0.4819 - recall: 0.4337 - val_loss: 0.7009 - val_binary_accuracy: 0.5833 - val_precision: 0.5263 - val_recall: 0.3614 ++
+
+
+
+
+
+
+In [30]:
+
+
+
+
+
+history.history["val_binary_accuracy"][0]
+
+
+
+
+
+
+
+
+Out[30]:
+
+
+0.5833333730697632+
+
+
+
+
+
+
+In [31]:
+
+
+
+
+
+# Quick summary of the best metrics according to binary_accuracy
+val = np.argmax(np.array(history.history["val_binary_accuracy"]))
+print(f"Binary accuracy: {history.history['val_binary_accuracy'][val]}")
+print(f"Precision: {history.history['val_precision'][val]}")
+print(f"Recall: {history.history['val_recall'][val]}")
+
+
+
+
+
+
+
+
+
+
+
+Binary accuracy: 0.5833333730697632 +Precision: 0.5263158082962036 +Recall: 0.3614457845687866 ++
+
+
+
+
+
+
+In [32]:
+
+
+
+
+
+plot_history(history)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+In [ ]:
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+In [ ]:
+
+
+
+
+
+
+