Class PILReader

monai/data/image_reader.py:1344–1445

Load common 2D image format (supports PNG, JPG, BMP) file or files from provided path. Args: converter: additional function to convert the image data after `read()`. for example, use `converter=lambda image: image.convert("LA")` to convert image format. reverse_

@require_pkg(pkg_name="PIL")
class PILReader(ImageReader):
    """
    Load common 2D image format (supports PNG, JPG, BMP) file or files from provided path.

    Args:
        converter: additional function to convert the image data after `read()`.
            for example, use `converter=lambda image: image.convert("LA")` to convert image format.
        reverse_indexing: whether to swap axis 0 and 1 after loading the array, this is enabled by default,
            so that output of the reader is consistent with the other readers. Set this option to ``False`` to use
            the PIL backend's original spatial axes convention.
        kwargs: additional args for `Image.open` API in `read()`, mode details about available args:
            https://pillow.readthedocs.io/en/stable/reference/Image.html#PIL.Image.open
    """

    def __init__(self, converter: Callable | None = None, reverse_indexing: bool = True, **kwargs):
        super().__init__()
        self.converter = converter
        self.reverse_indexing = reverse_indexing
        self.kwargs = kwargs

    def verify_suffix(self, filename: Sequence[PathLike] | PathLike) -> bool:
        """
        Verify whether the specified file or files format is supported by PIL reader.

        Args:
            filename: file name or a list of file names to read.
                if a list of files, verify all the suffixes.
        """
        suffixes: Sequence[str] = ["png", "jpg", "jpeg", "bmp"]
        return has_pil and is_supported_format(filename, suffixes)

    def read(self, data: Sequence[PathLike] | PathLike | np.ndarray, **kwargs):
        """
        Read image data from specified file or files, it can read a list of images
        and stack them together as multi-channel data in `get_data()`.
        Note that the returned object is PIL image or list of PIL image.

        Args:
            data: file name or a list of file names to read.
            kwargs: additional args for `Image.open` API in `read()`, will override `self.kwargs` for existing keys.
                Mode details about available args:
                https://pillow.readthedocs.io/en/stable/reference/Image.html#PIL.Image.open

        """
        img_: list[PILImage.Image] = []

        filenames: Sequence[PathLike] = ensure_tuple(data)
        kwargs_ = self.kwargs.copy()
        kwargs_.update(kwargs)
        for name in filenames:
            img = PILImage.open(name, **kwargs_)
            if callable(self.converter):
                img = self.converter(img)
            img_.append(img)

        return img_ if len(filenames) > 1 else img_[0]

    def get_data(self, img) -> tuple[np.ndarray, dict]: