예제 #1
0
def train(model_dir, results_subdir, random_seed, resolution):
    np.random.seed(random_seed)
    tf.set_random_seed(np.random.randint(1 << 31))
    session_conf = tf.ConfigProto(intra_op_parallelism_threads=1,
                                  inter_op_parallelism_threads=1)
    session_conf.gpu_options.allow_growth = True
    sess = tf.Session(graph=tf.get_default_graph(), config=session_conf)
    set_session(sess)

    # parser config
    config_file = model_dir + "/config.ini"
    print("Config File Path:", config_file, flush=True)
    assert os.path.isfile(config_file)
    cp = ConfigParser()
    cp.read(config_file)

    # default config
    base_model_name = cp["DEFAULT"].get("base_model_name")

    # train config
    path_model_base_weights = cp["TRAIN"].get("path_model_base_weights")
    use_trained_model_weights = cp["TRAIN"].getboolean(
        "use_trained_model_weights")
    use_best_weights = cp["TRAIN"].getboolean("use_best_weights")
    output_weights_name = cp["TRAIN"].get("output_weights_name")
    epochs = cp["TRAIN"].getint("epochs")
    batch_size = cp["TRAIN"].getint("batch_size")
    initial_learning_rate = cp["TRAIN"].getfloat("initial_learning_rate")
    image_dimension = cp["TRAIN"].getint("image_dimension")
    patience_reduce_lr = cp["TRAIN"].getint("patience_reduce_lr")
    min_lr = cp["TRAIN"].getfloat("min_lr")
    positive_weights_multiply = cp["TRAIN"].getfloat(
        "positive_weights_multiply")
    patience = cp["TRAIN"].getint("patience")
    samples_per_epoch = cp["TRAIN"].getint("samples_per_epoch")
    reduce_lr = cp["TRAIN"].getfloat("reduce_lr")

    print("** DenseNet input resolution:", image_dimension, flush=True)
    print("** GAN image resolution:", resolution, flush=True)
    print("** Patience epochs", patience, flush=True)
    print("** Samples per epoch:", samples_per_epoch, flush=True)

    log2_record = int(np.log2(resolution))
    record_file_ending = "*" + np.str(log2_record) + ".tfrecords"
    print("** Resolution ",
          resolution,
          " corresponds to ",
          record_file_ending,
          " TFRecord file.",
          flush=True)

    output_dir = os.path.join(
        results_subdir,
        "classification_results_res_" + np.str(2**log2_record) + "/train")
    print("Output Directory:", output_dir, flush=True)
    if not os.path.isdir(output_dir):
        os.makedirs(output_dir)

    # if previously trained weights is used, never re-split
    if use_trained_model_weights:
        print("** use trained model weights **", flush=True)
        training_stats_file = os.path.join(output_dir, ".training_stats.json")
        if os.path.isfile(training_stats_file):
            # TODO: add loading previous learning rate?
            training_stats = json.load(open(training_stats_file))
        else:
            training_stats = {}
    else:
        # start over
        training_stats = {}

    show_model_summary = cp["TRAIN"].getboolean("show_model_summary")
    running_flag_file = os.path.join(output_dir, ".training.lock")
    if os.path.isfile(running_flag_file):
        raise RuntimeError("A process is running in this directory!!!")
    else:
        open(running_flag_file, "a").close()

    try:
        print("backup config file to", output_dir, flush=True)
        shutil.copy(config_file,
                    os.path.join(output_dir,
                                 os.path.split(config_file)[1]))

        tfrecord_dir_tr = os.path.join(results_subdir[:-4], "train")
        tfrecord_dir_vl = os.path.join(results_subdir[:-4], "valid")

        shutil.copy(tfrecord_dir_tr + "/train.csv", output_dir)
        shutil.copy(tfrecord_dir_vl + "/valid.csv", output_dir)

        # Get class names
        class_names = get_class_names(output_dir, "train")

        # get train sample counts
        train_counts, train_pos_counts = get_sample_counts(
            output_dir, "train", class_names)
        valid_counts, _ = get_sample_counts(output_dir, "valid", class_names)

        print("Total Training Data:", train_counts, flush=True)
        print("Total Validation Data:", valid_counts, flush=True)
        train_steps = int(min(samples_per_epoch, train_counts) / batch_size)
        print("** train_steps:", train_steps, flush=True)
        validation_steps = int(np.floor(valid_counts / batch_size))
        print("** validation_steps:", validation_steps, flush=True)

        # compute class weights
        print("** compute class weights from training data **", flush=True)
        class_weights = get_class_weights(
            train_counts,
            train_pos_counts,
            multiply=positive_weights_multiply,
        )
        print("** class_weights **", flush=True)
        print(class_weights)

        print("** load model **", flush=True)
        if use_trained_model_weights:
            if use_best_weights:
                model_weights_file = os.path.join(
                    output_dir, "best_" + output_weights_name)
            else:
                model_weights_file = os.path.join(output_dir,
                                                  output_weights_name)
        else:
            model_weights_file = None

        # Use downloaded weights
        if os.path.isfile(path_model_base_weights):
            base_weights = path_model_base_weights
            print("** Base weights will be loaded.", flush=True)
        else:
            base_weights = None
            print("** No Base weights.", flush=True)

        # Get Model
        # ------------------------------------
        input_shape = (image_dimension, image_dimension, 3)
        img_input = Input(shape=input_shape)

        base_model = DenseNet121(include_top=False,
                                 weights=base_weights,
                                 input_tensor=img_input,
                                 input_shape=input_shape,
                                 pooling="avg")

        x = base_model.output
        predictions = Dense(len(class_names),
                            activation="sigmoid",
                            name="predictions")(x)
        model = Model(inputs=img_input, outputs=predictions)

        if use_trained_model_weights and model_weights_file != None:
            print("** load model weights_path:",
                  model_weights_file,
                  flush=True)
            model.load_weights(model_weights_file)
        # ------------------------------------

        if show_model_summary:
            print(model.summary())

        print("** create image generators", flush=True)
        train_seq = TFWrapper(tfrecord_dir=tfrecord_dir_tr,
                              record_file_endings=record_file_ending,
                              batch_size=batch_size,
                              model_target_size=(image_dimension,
                                                 image_dimension),
                              steps=train_steps,
                              augment=True,
                              shuffle=True,
                              prefetch=True,
                              repeat=True)

        valid_seq = TFWrapper(tfrecord_dir=tfrecord_dir_vl,
                              record_file_endings=record_file_ending,
                              batch_size=batch_size,
                              model_target_size=(image_dimension,
                                                 image_dimension),
                              steps=None,
                              augment=False,
                              shuffle=False,
                              prefetch=True,
                              repeat=True)

        # Initialise train and valid iterats
        print("** Initialise train and valid iterators", flush=True)
        train_seq.initialise()
        valid_seq.initialise()

        output_weights_path = os.path.join(output_dir, output_weights_name)
        print("** set output weights path to:",
              output_weights_path,
              flush=True)

        print("** SINGLE_gpu_model is used!", flush=True)
        model_train = model
        checkpoint = ModelCheckpoint(
            output_weights_path,
            save_weights_only=True,
            save_best_only=False,
            verbose=1,
        )

        print("** compile model with class weights **", flush=True)
        optimizer = Adam(lr=initial_learning_rate)
        model_train.compile(optimizer=optimizer, loss="binary_crossentropy")

        auroc = MultipleClassAUROC(sequence=valid_seq,
                                   class_names=class_names,
                                   weights_path=output_weights_path,
                                   stats=training_stats,
                                   early_stop_p=patience,
                                   learn_rate_p=patience_reduce_lr,
                                   learn_rate_f=reduce_lr,
                                   min_lr=min_lr,
                                   workers=0)

        callbacks = [
            checkpoint,
            TensorBoard(log_dir=os.path.join(output_dir, "logs"),
                        batch_size=batch_size), auroc
        ]

        print("** start training **", flush=True)
        history = model_train.fit_generator(
            generator=train_seq,
            steps_per_epoch=train_steps,
            epochs=epochs,
            validation_data=valid_seq,
            validation_steps=validation_steps,
            callbacks=callbacks,
            class_weight=class_weights,
            workers=0,
            shuffle=False,
        )

        # dump history
        print("** dump history **", flush=True)
        with open(os.path.join(output_dir, "history.pkl"), "wb") as f:
            pickle.dump({
                "history": history.history,
                "auroc": auroc.aurocs,
            }, f)
        print("** done! **", flush=True)

    finally:
        os.remove(running_flag_file)
예제 #2
0
def train_rsna_clf(train_data=None, validation_data=None, remove_running=True):
    # parser config
    config_file = "./config.ini"
    cp = ConfigParser()
    cp.read(config_file)

    # default config
    output_dir = cp["DEFAULT"].get("output_dir")
    image_source_dir = cp["DEFAULT"].get("image_source_dir")
    base_model_name = cp["DEFAULT"].get("base_model_name")
    class_names1 = cp["DEFAULT"].get("class_names1").split(",")
    class_names2 = cp["DEFAULT"].get("class_names2").split(",")

    # train config
    train_image_source_dir = cp["TRAIN"].get("train_image_source_dir")
    train_class_info = cp["TRAIN"].get("train_class_info")
    train_box_info = cp["TRAIN"].get("train_box_info")
    use_base_model_weights = cp["TRAIN"].getboolean("use_base_model_weights")
    use_trained_model_weights = cp["TRAIN"].getboolean(
        "use_trained_model_weights")
    use_best_weights = cp["TRAIN"].getboolean("use_best_weights")
    input_weights_name = cp["TRAIN"].get("input_weights_name")
    output_weights_name = cp["TRAIN"].get("output_weights_name")
    epochs = cp["TRAIN"].getint("epochs")
    batch_size = cp["TRAIN"].getint("batch_size")
    initial_learning_rate = cp["TRAIN"].getfloat("initial_learning_rate")
    generator_workers = cp["TRAIN"].getint("generator_workers")
    image_dimension = cp["TRAIN"].getint("image_dimension")
    train_steps = cp["TRAIN"].get("train_steps")
    patience_reduce_lr = cp["TRAIN"].getint("patience_reduce_lr")
    min_lr = cp["TRAIN"].getfloat("min_lr")
    validation_steps = cp["TRAIN"].get("validation_steps")
    positive_weights_multiply = cp["TRAIN"].getfloat(
        "positive_weights_multiply")
    dataset_csv_dir = cp["TRAIN"].get("dataset_csv_dir")
    # if previously trained weights is used, never re-split
    if use_trained_model_weights:
        # resuming mode
        print("** use trained model weights **")
        # load training status for resuming
        training_stats_file = os.path.join(output_dir, ".training_stats.json")
        if os.path.isfile(training_stats_file):
            # TODO: add loading previous learning rate?
            training_stats = json.load(open(training_stats_file))
        else:
            training_stats = {}
    else:
        # start over
        training_stats = {}

    show_model_summary = cp["TRAIN"].getboolean("show_model_summary")
    # end parser config

    # check output_dir, create it if not exists
    if not os.path.isdir(output_dir):
        os.makedirs(output_dir)

    running_flag_file = os.path.join(output_dir, ".training.lock")
    if os.path.isfile(running_flag_file):
        if remove_running:
            os.remove(running_flag_file)
            open(running_flag_file, "a").close()
        else:
            raise RuntimeError("A process is running in this directory!!!")
    else:
        open(running_flag_file, "a").close()

    try:
        print(f"backup config file to {output_dir}")
        shutil.copy(config_file,
                    os.path.join(output_dir,
                                 os.path.split(config_file)[1]))

        # get train/dev sample counts
        train_counts, train_pos_counts = get_sample_counts(
            train_data.df, class_names2)
        validation_counts, _ = get_sample_counts(validation_data.df,
                                                 class_names2)

        # compute steps
        if train_steps == "auto":
            train_steps = int(train_counts / batch_size)
        else:
            try:
                train_steps = int(train_steps)
            except ValueError:
                raise ValueError(f"""
                train_steps: {train_steps} is invalid,
                please use 'auto' or integer.
                """)
        print(f"** train_steps: {train_steps} **")

        if validation_steps == "auto":
            validation_steps = int(validation_counts / batch_size)
        else:
            try:
                validation_steps = int(validation_steps)
            except ValueError:
                raise ValueError(f"""
                validation_steps: {validation_steps} is invalid,
                please use 'auto' or integer.
                """)
        print(f"** validation_steps: {validation_steps} **")

        # compute class weights
        print("** compute class weights from training data **")
        class_weights = get_class_weights(
            train_counts,
            train_pos_counts,
            multiply=positive_weights_multiply,
        )
        print("** class_weights **")
        print(class_weights)

        print("** load model **")
        if use_trained_model_weights:
            if use_best_weights:
                model_weights_file = os.path.join(
                    output_dir, f"best_{input_weights_name}")
            else:
                model_weights_file = os.path.join(output_dir,
                                                  input_weights_name)
        else:
            model_weights_file = None

        model_factory = ModelFactory()
        model = model_factory.get_model(
            class_names1,
            model_name=base_model_name,
            use_base_weights=use_base_model_weights,
            weights_path=model_weights_file,
            input_shape=(image_dimension, image_dimension, 3))
        model = modify_last_layer(model, class_names2)

        if show_model_summary:
            print(model.summary())

        train_sq = AugmentedLabelSequence_clf(
            train_data,
            batch_size=batch_size,
            target_size=(image_dimension, image_dimension),
            augmenter=augmenter,
            steps=train_steps,
        )
        validation_sq = AugmentedLabelSequence_clf(
            validation_data,
            batch_size=batch_size,
            target_size=(image_dimension, image_dimension),
            augmenter=augmenter,
            steps=validation_steps,
        )

        output_weights_path = os.path.join(output_dir, output_weights_name)
        print(f"** set output weights path to: {output_weights_path} **")

        print("** check multiple gpu availability **")
        gpus = len(os.getenv("CUDA_VISIBLE_DEVICES", "1").split(","))
        if gpus > 1:
            print(f"** multi_gpu_model is used! gpus={gpus} **")
            model_train = multi_gpu_model(model, gpus)
            # FIXME: currently (Keras 2.1.2) checkpoint doesn't work with multi_gpu_model
            checkpoint = MultiGPUModelCheckpoint(
                filepath=output_weights_path,
                base_model=model,
            )
        else:
            model_train = model
            checkpoint = ModelCheckpoint(
                output_weights_path,
                save_weights_only=True,
                save_best_only=True,
                verbose=1,
            )

        print("** compile model with class weights **")
        optimizer = Adam(lr=initial_learning_rate)
        model_train.compile(optimizer=optimizer, loss="binary_crossentropy")
        auroc = MultipleClassAUROC(
            sequence=validation_sq,
            class_names=class_names2,
            weights_path=output_weights_path,
            stats=training_stats,
            workers=generator_workers,
        )
        callbacks = [
            checkpoint,
            TensorBoard(log_dir=os.path.join(output_dir, "logs"),
                        batch_size=batch_size),
            ReduceLROnPlateau(monitor='val_loss',
                              factor=0.1,
                              patience=patience_reduce_lr,
                              verbose=1,
                              mode="min",
                              min_lr=min_lr),
            auroc,
        ]

        print("** start training **")
        history = model_train.fit_generator(
            generator=train_sq,
            steps_per_epoch=train_steps,
            epochs=epochs,
            validation_data=validation_sq,
            validation_steps=validation_steps,
            callbacks=callbacks,
            class_weight=class_weights,
            workers=generator_workers,
            shuffle=False,
        )

        # dump history
        print("** dump history **")
        with open(os.path.join(output_dir, "history.pkl"), "wb") as f:
            pickle.dump({
                "history": history.history,
                "auroc": auroc.aurocs,
            }, f)
        print("** done! **")

    finally:
        os.remove(running_flag_file)
예제 #3
0
def main():
    # parser config
    config_file = "./config.ini"
    cp = ConfigParser()
    cp.read(config_file)

    # default config
    output_dir = cp["DEFAULT"].get("output_dir")
    image_source_dir = cp["DEFAULT"].get("image_source_dir")
    train_patient_count = cp["DEFAULT"].getint("train_patient_count")
    dev_patient_count = cp["DEFAULT"].getint("dev_patient_count")
    data_entry_file = cp["DEFAULT"].get("data_entry_file")
    class_names = cp["DEFAULT"].get("class_names").split(",")

    # train config
    use_base_model_weights = cp["TRAIN"].getboolean("use_base_model_weights")
    use_trained_model_weights = cp["TRAIN"].getboolean(
        "use_trained_model_weights")
    use_best_weights = cp["TRAIN"].getboolean("use_best_weights")
    output_weights_name = cp["TRAIN"].get("output_weights_name")
    epochs = cp["TRAIN"].getint("epochs")
    batch_size = cp["TRAIN"].getint("batch_size")
    initial_learning_rate = cp["TRAIN"].getfloat("initial_learning_rate")
    train_steps = cp["TRAIN"].get("train_steps")
    patience_reduce_lr = cp["TRAIN"].getint("patience_reduce_lr")
    validation_steps = cp["TRAIN"].get("validation_steps")
    positive_weights_multiply = cp["TRAIN"].getfloat(
        "positive_weights_multiply")
    use_class_balancing = cp["TRAIN"].getboolean("use_class_balancing")
    use_default_split = cp["TRAIN"].getboolean("use_default_split")
    # if previously trained weights is used, never re-split
    if use_trained_model_weights:
        # resuming mode
        print(
            "** use trained model weights, turn on use_skip_split automatically **"
        )
        use_skip_split = True
        # load training status for resuming
        training_stats_file = os.path.join(output_dir, ".training_stats.json")
        if os.path.isfile(training_stats_file):
            # TODO: add loading previous learning rate?
            training_stats = json.load(open(training_stats_file))
        else:
            training_stats = {}
    else:
        # start over
        use_skip_split = cp["TRAIN"].getboolean("use_skip_split ")
        training_stats = {}

    split_dataset_random_state = cp["TRAIN"].getint(
        "split_dataset_random_state")
    show_model_summary = cp["TRAIN"].getboolean("show_model_summary")
    # end parser config

    # check output_dir, create it if not exists
    if not os.path.isdir(output_dir):
        os.makedirs(output_dir)

    running_flag_file = os.path.join(output_dir, ".training.lock")
    if os.path.isfile(running_flag_file):
        raise RuntimeError("A process is running in this directory!!!")
    else:
        open(running_flag_file, "a").close()

    try:
        print(f"backup config file to {output_dir}")
        shutil.copy(config_file,
                    os.path.join(output_dir,
                                 os.path.split(config_file)[1]))

        # split train/dev/test
        if use_default_split:
            datasets = ["train", "dev", "test"]
            for dataset in datasets:
                shutil.copy(f"./data/default_split/{dataset}.csv", output_dir)
        elif not use_skip_split:
            print("** split dataset **")
            split_data(
                data_entry_file,
                class_names,
                train_patient_count,
                dev_patient_count,
                output_dir,
                split_dataset_random_state,
            )

        # get train/dev sample counts
        train_counts, train_pos_counts = get_sample_counts(
            output_dir, "train", class_names)
        dev_counts, _ = get_sample_counts(output_dir, "dev", class_names)

        # compute steps
        if train_steps == "auto":
            train_steps = int(train_counts / batch_size)
        else:
            try:
                train_steps = int(train_steps)
            except ValueError:
                raise ValueError(f"""
                train_steps: {train_steps} is invalid,
                please use 'auto' or integer.
                """)
        print(f"** train_steps: {train_steps} **")

        if validation_steps == "auto":
            validation_steps = int(dev_counts / batch_size)
        else:
            try:
                validation_steps = int(validation_steps)
            except ValueError:
                raise ValueError(f"""
                validation_steps: {validation_steps} is invalid,
                please use 'auto' or integer.
                """)
        print(f"** validation_steps: {validation_steps} **")

        # compute class weights
        print("** compute class weights from training data **")
        class_weights = get_class_weights(
            train_counts,
            train_pos_counts,
            multiply=positive_weights_multiply,
            use_class_balancing=use_class_balancing)
        print("** class_weights **")
        for c, w in class_weights.items():
            print(f"  {c}: {w}")

        print("** load model **")
        if use_base_model_weights:
            base_model_weights_file = cp["TRAIN"].get(
                "base_model_weights_file")
        else:
            base_model_weights_file = None
        if use_trained_model_weights:
            if use_best_weights:
                model_weights_file = os.path.join(
                    output_dir, f"best_{output_weights_name}")
            else:
                model_weights_file = os.path.join(output_dir,
                                                  output_weights_name)
        else:
            model_weights_file = None
        model = get_model(class_names, base_model_weights_file,
                          model_weights_file)
        if show_model_summary:
            print(model.summary())

        # recreate symlink folder for ImageDataGenerator
        symlink_dir_name = "image_links"
        create_symlink(image_source_dir, output_dir, symlink_dir_name)

        print("** create image generators **")
        train_data_path = f"{output_dir}/{symlink_dir_name}/train/"
        train_generator = custom_image_generator(
            ImageDataGenerator(horizontal_flip=True, rescale=1. / 255),
            train_data_path,
            batch_size=batch_size,
            class_names=class_names,
        )
        dev_data_path = f"{output_dir}/{symlink_dir_name}/dev/"
        dev_generator = custom_image_generator(
            ImageDataGenerator(horizontal_flip=True, rescale=1. / 255),
            dev_data_path,
            batch_size=batch_size,
            class_names=class_names,
        )

        output_weights_path = os.path.join(output_dir, output_weights_name)
        print(f"** set output weights path to: {output_weights_path} **")

        print("** check multiple gpu availability **")
        gpus = len(os.getenv("CUDA_VISIBLE_DEVICES", "1").split(","))
        if gpus > 1:
            print(f"** multi_gpu_model is used! gpus={gpus} **")
            model_train = multi_gpu_model(model, gpus)
            # FIXME: currently (Keras 2.1.2) checkpoint doesn't work with multi_gpu_model
            checkpoint = MultiGPUModelCheckpoint(
                filepath=output_weights_path,
                base_model=model,
            )
        else:
            model_train = model
            checkpoint = ModelCheckpoint(output_weights_path)

        print("** compile model with class weights **")
        optimizer = Adam(lr=initial_learning_rate)
        model_train.compile(optimizer=optimizer, loss="binary_crossentropy")
        auroc = MultipleClassAUROC(
            generator=dev_generator,
            steps=validation_steps,
            class_names=class_names,
            weights_path=output_weights_path,
            stats=training_stats,
        )
        callbacks = [
            checkpoint,
            TensorBoard(log_dir=os.path.join(output_dir, "logs"),
                        batch_size=batch_size),
            ReduceLROnPlateau(monitor='val_loss',
                              factor=0.1,
                              patience=patience_reduce_lr,
                              verbose=1),
            auroc,
        ]

        print("** training start **")
        history = model_train.fit_generator(
            generator=train_generator,
            steps_per_epoch=train_steps,
            epochs=epochs,
            validation_data=dev_generator,
            validation_steps=validation_steps,
            callbacks=callbacks,
            class_weight=class_weights,
        )

        # dump history
        print("** dump history **")
        with open(os.path.join(output_dir, "history.pkl"), "wb") as f:
            pickle.dump({
                "history": history.history,
                "auroc": auroc.aurocs,
            }, f)
        print("** done! **")

    finally:
        os.remove(running_flag_file)
예제 #4
0
def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--model_epoch', type=int, default=0)
    args = parser.parse_args()

    # Set Parameter #
    base_model_name = "DenseNet121"
    use_base_model_weights = True
    weights_path = None
    image_dimension = 224
    batch_size = 32
    epochs = 20
    class_names = ["Nodule", "Pneumothorax"]
    csv_path = './data/classification'
    image_source_dir = '/media/nfs/CXR/NIH/chest_xrays/NIH/data/images_1024x1024/'
    augmenter = None
    #  If train_steps is set to None, will calculate train steps by len(train)/batch_size
    train_steps = None
    positive_weights_multiply = 1
    outputs_path = './experiments/ae'
    weights_name = f'weights{args.model_epoch}.h5'
    output_weights_path = os.path.join(outputs_path, weights_name)
    initial_learning_rate = 0.0001
    training_stats = {}

    # Get Sample and Total Count From Training Data and Compute Class Weights #
    train_counts, train_pos_counts = get_sample_counts(csv_path, "train",
                                                       class_names)
    if train_steps == None:
        train_steps = int(train_counts / batch_size)
    dev_counts, _ = get_sample_counts(csv_path, "test", class_names)
    validation_steps = int(dev_counts / batch_size)
    print('***Compute Class Weights***')
    class_weights = get_class_weights(train_counts,
                                      train_pos_counts,
                                      multiply=positive_weights_multiply)
    print(class_weights)

    # Create Image Sequence #

    train_sequence = AugmentedImageSequence(
        dataset_csv_file=os.path.join(csv_path, "train.csv"),
        class_names=class_names,
        source_image_dir=image_source_dir,
        batch_size=batch_size,
        target_size=(image_dimension, image_dimension),
        augmenter=augmenter,
        steps=train_steps,
        model_epoch=args.model_epoch)

    validation_sequence = AugmentedImageSequence(
        dataset_csv_file=os.path.join(csv_path, "test.csv"),
        class_names=class_names,
        source_image_dir=image_source_dir,
        batch_size=batch_size,
        target_size=(image_dimension, image_dimension),
        augmenter=augmenter,
        steps=validation_steps,
        shuffle_on_epoch_end=False,
        model_epoch=args.model_epoch)

    # Build Model #
    factory = ModelFactory()
    model = factory.get_model(class_names,
                              model_name=base_model_name,
                              use_base_weights=use_base_model_weights,
                              weights_path=None,
                              input_shape=(image_dimension, image_dimension,
                                           3))

    print("** check multiple gpu availability **")
    gpus = len(os.getenv("CUDA_VISIBLE_DEVICES", "1").split(","))
    if gpus > 1:
        print("** multi_gpu_model is used! gpus={gpus} **")
        model_train = multi_gpu_model(model, gpus)
        # FIXME: currently (Keras 2.1.2) checkpoint doesn't work with multi_gpu_model
        checkpoint = MultiGPUModelCheckpoint(
            filepath=output_weights_path,
            base_model=model,
        )
    else:
        model_train = model
        checkpoint = ModelCheckpoint(
            output_weights_path,
            save_weights_only=True,
            save_best_only=True,
            verbose=1,
        )

    auroc = MultipleClassAUROC(sequence=validation_sequence,
                               class_names=class_names,
                               weights_path=output_weights_path,
                               stats=training_stats,
                               workers=8,
                               model_epoch=args.model_epoch)
    callbacks = [
        checkpoint,
        TensorBoard(log_dir=os.path.join(outputs_path, "logs"),
                    batch_size=batch_size),
        ReduceLROnPlateau(monitor='val_loss',
                          factor=0.1,
                          patience=1,
                          verbose=1,
                          mode="min",
                          min_lr=1e-8),
        auroc,
    ]

    # Compile Model #
    print('*** Start Compiling ***')
    optimizer = Adam(lr=initial_learning_rate)
    model_train.compile(optimizer=optimizer, loss="binary_crossentropy")

    # Train #
    print("** start training **")
    history = model_train.fit_generator(
        generator=train_sequence,
        steps_per_epoch=train_steps,
        epochs=epochs,
        validation_data=validation_sequence,
        validation_steps=validation_steps,
        callbacks=callbacks,
        class_weight=class_weights,
        workers=8,
        shuffle=False,
    )
    # dump history
    print("** dump history **")
    with open(os.path.join(outputs_path, f"history{args.model_epoch}.pkl"),
              "wb") as f:
        pickle.dump({
            "history": history.history,
            "auroc": auroc.aurocs,
        }, f)
    print("** done! **")