Python tensorflow.keras.models() Examples

def compute_backbone_shapes(config, image_shape):
    """Computes the width and height of each stage of the backbone network.

    Returns:
        [N, (height, width)]. Where N is the number of stages
    """
    if callable(config.BACKBONE):
        return config.COMPUTE_BACKBONE_SHAPE(image_shape)

    # Currently supports ResNet only
    assert config.BACKBONE in ["resnet50", "resnet101"]
    return np.array(
        [[int(math.ceil(image_shape[0] / stride)),
            int(math.ceil(image_shape[1] / stride))]
            for stride in config.BACKBONE_STRIDES])


############################################################
#  Resnet Graph
############################################################

# Code adopted from:
# https://github.com/fchollet/deep-learning-models/blob/master/resnet50.py 

def get_imagenet_weights(self):
        """Downloads ImageNet trained weights from Keras.
        Returns path to weights file.
        """
        from keras.utils.data_utils import get_file
        TF_WEIGHTS_PATH_NO_TOP = 'https://github.com/fchollet/deep-learning-models/'\
                                 'releases/download/v0.2/'\
                                 'resnet50_weights_tf_dim_ordering_tf_kernels_notop.h5'
        weights_path = get_file('resnet50_weights_tf_dim_ordering_tf_kernels_notop.h5',
                                TF_WEIGHTS_PATH_NO_TOP,
                                cache_subdir='models',
                                md5_hash='a268eb855778b3df3c7506639542a6af')
        return weights_path 

def get_preprocessing(name):
    preprocess_input = Backbones.get_preprocessing(name)
    # add bakcend, models, layers, utils submodules in kwargs
    preprocess_input = inject_global_submodules(preprocess_input)
    # delete other kwargs
    # keras-applications preprocessing raise an error if something
    # except `backend`, `layers`, `models`, `utils` passed in kwargs
    preprocess_input = filter_kwargs(preprocess_input)
    return preprocess_input 

def filter_kwargs(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        new_kwargs = {k: v for k, v in kwargs.items() if k in ['backend', 'layers', 'models', 'utils']}
        return func(*args, **new_kwargs)

    return wrapper 

def inject_global_submodules(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = _KERAS_BACKEND
        kwargs['layers'] = _KERAS_LAYERS
        kwargs['models'] = _KERAS_MODELS
        kwargs['utils'] = _KERAS_UTILS
        return func(*args, **kwargs)

    return wrapper 

def inject_tfkeras_modules(func):
    import tensorflow.keras as tfkeras
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = tfkeras.backend
        kwargs['layers'] = tfkeras.layers
        kwargs['models'] = tfkeras.models
        kwargs['utils'] = tfkeras.utils
        return func(*args, **kwargs)

    return wrapper 

def inject_keras_modules(func):
    import keras
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = keras.backend
        kwargs['layers'] = keras.layers
        kwargs['models'] = keras.models
        kwargs['utils'] = keras.utils
        return func(*args, **kwargs)

    return wrapper 

def get_submodules_from_kwargs(kwargs):
    backend = kwargs.get('backend', _KERAS_BACKEND)
    layers = kwargs.get('layers', _KERAS_LAYERS)
    models = kwargs.get('models', _KERAS_MODELS)
    utils = kwargs.get('utils', _KERAS_UTILS)
    for key in kwargs.keys():
        if key not in ['backend', 'layers', 'models', 'utils']:
            raise TypeError('Invalid keyword argument: %s', key)
    return backend, layers, models, utils 

def decode_predictions(preds, top=5, **kwargs):
    """Decodes the prediction of an ImageNet model.
    # Arguments
        preds: Numpy tensor encoding a batch of predictions.
        top: Integer, how many top-guesses to return.
    # Returns
        A list of lists of top class prediction tuples
        `(class_name, class_description, score)`.
        One list of tuples per sample in batch input.
    # Raises
        ValueError: In case of invalid shape of the `pred` array
            (must be 2D).
    """
    global CLASS_INDEX

    if len(preds.shape) != 2 or preds.shape[1] != 1000:
        raise ValueError('`decode_predictions` expects '
                         'a batch of predictions '
                         '(i.e. a 2D array of shape (samples, 1000)). '
                         'Found array with shape: ' + str(preds.shape))
    if CLASS_INDEX is None:
        fpath = keras_utils.get_file(
            'imagenet_class_index.json',
            CLASS_INDEX_PATH,
            cache_subdir='models',
            file_hash='c2c37ea517e94d9795004a39431a14cb')
        with open(fpath) as f:
            CLASS_INDEX = json.load(f)
    results = []
    for pred in preds:
        top_indices = pred.argsort()[-top:][::-1]
        result = [tuple(CLASS_INDEX[str(i)]) + (pred[i],) for i in top_indices]
        result.sort(key=lambda x: x[2], reverse=True)
        results.append(result)
    return results 

def summary(self, *args, **kwargs):
        """Override summary() to display summaries of both, the wrapper
        and inner models."""
        super(ParallelModel, self).summary(*args, **kwargs)
        self.inner_model.summary(*args, **kwargs) 

def get_kwargs():
        return {
            'backend': tfkeras.backend,
            'layers': tfkeras.layers,
            'models': tfkeras.models,
            'utils': tfkeras.utils,
        } 

def inject_tfkeras_modules(func):
    import tensorflow.keras as tfkeras
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = tfkeras.backend
        kwargs['layers'] = tfkeras.layers
        kwargs['models'] = tfkeras.models
        kwargs['utils'] = tfkeras.utils
        return func(*args, **kwargs)

    return wrapper 

def inject_keras_modules(func):
    import keras
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = keras.backend
        kwargs['layers'] = keras.layers
        kwargs['models'] = keras.models
        kwargs['utils'] = keras.utils
        return func(*args, **kwargs)

    return wrapper 

def get_submodules_from_kwargs(kwargs):
    backend = kwargs.get('backend', _KERAS_BACKEND)
    layers = kwargs.get('layers', _KERAS_LAYERS)
    models = kwargs.get('models', _KERAS_MODELS)
    utils = kwargs.get('utils', _KERAS_UTILS)
    for key in kwargs.keys():
        if key not in ['backend', 'layers', 'models', 'utils']:
            raise TypeError('Invalid keyword argument: %s', key)
    return backend, layers, models, utils 

def inject_tfkeras_modules(func):
    import tensorflow.keras as tfkeras
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = tfkeras.backend
        kwargs['layers'] = tfkeras.layers
        kwargs['models'] = tfkeras.models
        kwargs['utils'] = tfkeras.utils
        return func(*args, **kwargs)

    return wrapper 

def inject_keras_modules(func):
    import keras
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        kwargs['backend'] = keras.backend
        kwargs['layers'] = keras.layers
        kwargs['models'] = keras.models
        kwargs['utils'] = keras.utils
        return func(*args, **kwargs)

    return wrapper 

def get_submodules_from_kwargs(kwargs):
    backend = kwargs.get('backend', _KERAS_BACKEND)
    layers = kwargs.get('layers', _KERAS_LAYERS)
    models = kwargs.get('models', _KERAS_MODELS)
    utils = kwargs.get('utils', _KERAS_UTILS)
    for key in kwargs.keys():
        if key not in ['backend', 'layers', 'models', 'utils']:
            raise TypeError('Invalid keyword argument: %s', key)
    return backend, layers, models, utils 

def load_model(input_model_path, input_json_path=None, input_yaml_path=None):
    if not Path(input_model_path).exists():
        raise FileNotFoundError(
            'Model file `{}` does not exist.'.format(input_model_path))
    try:
        model = keras.models.load_model(input_model_path)
        return model
    except FileNotFoundError as err:
        logging.error('Input mode file (%s) does not exist.', FLAGS.input_model)
        raise err
    except ValueError as wrong_file_err:
        if input_json_path:
            if not Path(input_json_path).exists():
                raise FileNotFoundError(
                    'Model description json file `{}` does not exist.'.format(
                        input_json_path))
            try:
                model = model_from_json(open(str(input_json_path)).read())
                model.load_weights(input_model_path)
                return model
            except Exception as err:
                logging.error("Couldn't load model from json.")
                raise err
        elif input_yaml_path:
            if not Path(input_yaml_path).exists():
                raise FileNotFoundError(
                    'Model description yaml file `{}` does not exist.'.format(
                        input_yaml_path))
            try:
                model = model_from_yaml(open(str(input_yaml_path)).read())
                model.load_weights(input_model_path)
                return model
            except Exception as err:
                logging.error("Couldn't load model from yaml.")
                raise err
        else:
            logging.error(
                'Input file specified only holds the weights, and not '
                'the model definition. Save the model using '
                'model.save(filename.h5) which will contain the network '
                'architecture as well as its weights. '
                'If the model is saved using the '
                'model.save_weights(filename) function, either '
                'input_model_json or input_model_yaml flags should be set to '
                'to import the network architecture prior to loading the '
                'weights. \n'
                'Check the keras documentation for more details '
                '(https://keras.io/getting-started/faq/)')
            raise wrong_file_err 

def set_framework(name):
    """Set framework for Segmentation Models

    Args:
        name (str): one of ``keras``, ``tf.keras``, case insensitive.

    Raises:
        ValueError: in case of incorrect framework name.
        ImportError: in case framework is not installed.

    """
    name = name.lower()

    if name == _KERAS_FRAMEWORK_NAME:
        import keras
        import efficientnet.keras  # init custom objects
    elif name == _TF_KERAS_FRAMEWORK_NAME:
        from tensorflow import keras
        import efficientnet.tfkeras  # init custom objects
    else:
        raise ValueError('Not correct module name `{}`, use `{}` or `{}`'.format(
            name, _KERAS_FRAMEWORK_NAME, _TF_KERAS_FRAMEWORK_NAME))

    global _KERAS_BACKEND, _KERAS_LAYERS, _KERAS_MODELS
    global _KERAS_UTILS, _KERAS_LOSSES, _KERAS_FRAMEWORK

    _KERAS_FRAMEWORK = name
    _KERAS_BACKEND = keras.backend
    _KERAS_LAYERS = keras.layers
    _KERAS_MODELS = keras.models
    _KERAS_UTILS = keras.utils
    _KERAS_LOSSES = keras.losses

    # allow losses/metrics get keras submodules
    base.KerasObject.set_submodules(
        backend=keras.backend,
        layers=keras.layers,
        models=keras.models,
        utils=keras.utils,
    )


# set default framework