mediapipe_model_maker.quantization.ds.Dataset

A generic dataset class for loading model training and evaluation dataset.

mediapipe_model_maker.quantization.ds.Dataset(
    tf_dataset: tf.data.Dataset, size: Optional[int] = None
)

For each ML task, such as image classification, text classification etc., a subclass can be derived from this class to provide task-specific data loading utilities.

Args
tf_dataset	A tf.data.Dataset object that contains a potentially large set of elements, where each element is a pair of (input_data, target). The input_data means the raw input data, like an image, a text etc., while the target means the ground truth of the raw input data, e.g. the classification label of the image etc.
size	The size of the dataset. tf.data.Dataset donesn't support a function to get the length directly since it's lazy-loaded and may be infinite.

Attributes

size

Returns the size of the dataset. Note that this function may return None becuase the exact size of the dataset isn't a necessary parameter to create an instance of this class, and tf.data.Dataset donesn't support a function to get the length directly since it's lazy-loaded and may be infinite. In most cases, however, when an instance of this class is created by helper functions like 'from_folder', the size of the dataset will be preprocessed, and this function can return an int representing the size of the dataset.

Methods

gen_tf_dataset

View source

gen_tf_dataset(
    batch_size: int = 1,
    is_training: bool = False,
    shuffle: bool = False,
    preprocess: Optional[Callable[..., Any]] = None,
    drop_remainder: bool = False
) -> tf.data.Dataset

Generates a batched tf.data.Dataset for training/evaluation.

Args
batch_size	An integer, the returned dataset will be batched by this size.
is_training	A boolean, when True, the returned dataset will be optionally shuffled and repeated as an endless dataset.
shuffle	A boolean, when True, the returned dataset will be shuffled to create randomness during model training.
preprocess	A function taking three arguments in order, feature, label and boolean is_training.
drop_remainder	boolean, whether the finally batch drops remainder.

Returns
A TF dataset ready to be consumed by Keras model.

split

View source

split(
    fraction: float
) -> Tuple[_DatasetT, _DatasetT]

Splits dataset into two sub-datasets with the given fraction.

Primarily used for splitting the data set into training and testing sets.

Args
fraction	A float value defines the fraction of the first returned subdataset in the original data.

Returns
The splitted two sub datasets.

__len__

View source

__len__()

Returns the number of element of the dataset.