Method __init__

monai/transforms/intensity/dictionary.py:313–352

Args: keys: keys of the corresponding items to be transformed. See also: :py:class:`monai.transforms.compose.MapTransform` offset: offset value to shift the intensity of image. safe: if `True`, then do safe dtype convert when intensity ove

(
        self,
        keys: KeysCollection,
        offset: float,
        safe: bool = False,
        factor_key: str | None = None,
        meta_keys: KeysCollection | None = None,
        meta_key_postfix: str = DEFAULT_POST_FIX,
        allow_missing_keys: bool = False,
    )

    backend = ShiftIntensity.backend

    def __init__(
        self,
        keys: KeysCollection,
        offset: float,
        safe: bool = False,
        factor_key: str | None = None,
        meta_keys: KeysCollection | None = None,
        meta_key_postfix: str = DEFAULT_POST_FIX,
        allow_missing_keys: bool = False,
    ) -> None:
        """
        Args:
            keys: keys of the corresponding items to be transformed.
                See also: :py:class:`monai.transforms.compose.MapTransform`
            offset: offset value to shift the intensity of image.
            safe: if `True`, then do safe dtype convert when intensity overflow. default to `False`.
                E.g., `[256, -12]` -> `[array(0), array(244)]`. If `True`, then `[256, -12]` -> `[array(255), array(0)]`.
            factor_key: if not None, use it as the key to extract a value from the corresponding
                metadata dictionary of `key` at runtime, and multiply the `offset` to shift intensity.
                Usually, `IntensityStatsd` transform can pre-compute statistics of intensity values
                and store in the metadata.
                it also can be a sequence of strings, map to `keys`.
            meta_keys: explicitly indicate the key of the corresponding metadata dictionary.
                used to extract the factor value is `factor_key` is not None.
                for example, for data with key `image`, the metadata by default is in `image_meta_dict`.
                the metadata is a dictionary object which contains: filename, original_shape, etc.
                it can be a sequence of string, map to the `keys`.
                if None, will try to construct meta_keys by `key_{meta_key_postfix}`.
            meta_key_postfix: if meta_keys is None, use `key_{postfix}` to fetch the metadata according
                to the key data, default is `meta_dict`, the metadata is a dictionary object.
                used to extract the factor value is `factor_key` is not None.
            allow_missing_keys: don't raise exception if key is missing.
        """
        super().__init__(keys, allow_missing_keys)
        self.factor_key = ensure_tuple_rep(factor_key, len(self.keys))
        self.meta_keys = ensure_tuple_rep(None, len(self.keys)) if meta_keys is None else ensure_tuple(meta_keys)
        if len(self.keys) != len(self.meta_keys):
            raise ValueError("meta_keys should have the same length as keys.")
        self.meta_key_postfix = ensure_tuple_rep(meta_key_postfix, len(self.keys))
        self.shifter = ShiftIntensity(offset, safe)

    def __call__(self, data) -> dict[Hashable, NdarrayOrTensor]:
        d = dict(data)