Function parse

brambox/boxes/util/convert.py:15–115

Parse any type of bounding box format. Args: fmt (str or class): Format from the :mod:`brambox.boxes.format ` dictionary box_file (list or string): Bounding box filename or array of bounding box file names identify (function, optional): Function to create

(fmt, box_file, identify=None, offset=0, stride=1, **kwargs)

def parse(fmt, box_file, identify=None, offset=0, stride=1, **kwargs):
    """ Parse any type of bounding box format.

    Args:
        fmt (str or class): Format from the :mod:`brambox.boxes.format <brambox.boxes>` dictionary
        box_file (list or string): Bounding box filename or array of bounding box file names
        identify (function, optional): Function to create an image identifier
        offset (int, optional): Skip images untill offset; Default **0**
        stride (int, optional): Only read every n&#x27;th file; Default **1**
        **kwargs: Keyword arguments that are passed to the parser

    Returns:
        dict: Dictionary containing the bounding boxes for every image ``{"image_id": [box, box, ...], ...}``

    Note:
        The ``identify`` function will be used to generate ``image_id`` tags. |br|
        If the format is of the type :any:`brambox.boxes.box.ParserType.SINGLE_FILE`,
        the identify function gets the existing ``image_id`` tags as input. The default is to not change the tags. |br|
        If the format is of the type :any:`brambox.boxes.box.ParserType.MULTI_FILE`,
        the identify function gets the path of the current file as input. The default is to get the name of the file without extensions.

    Warning:
        The ``box_file`` parameter can be either a list or string. |br|
        If the format is of the type :any:`brambox.boxes.box.ParserType.SINGLE_FILE`,
        then only a string is accepted and this is used as the filename. |br|
        If the format is of the type :any:`brambox.boxes.box.ParserType.MULTI_FILE`,
        then you can either pass a list or a string.
        A list will be used as is, namely every string of the list gets used as a filename.
        If you use a string, it will first be expanded with the :func:`~brambox.boxes.expand` function
        to generate a list of strings. This expand function can take optional stride and offset parameters,
        which can be passed via keyword arguments.
    """

    # Create parser
    if type(fmt) is str:
        try:
            parser = formats[fmt](**kwargs)
        except KeyError:
            raise TypeError(f'Invalid parser {fmt}')
    elif issubclass(fmt, Parser):
        parser = fmt(**kwargs)
    else:
        raise TypeError(f'Invalid parser {fmt}')

    # Parse bounding boxes
    if parser.parser_type == ParserType.SINGLE_FILE:
        if type(box_file) is not str:
            raise TypeError(f'Parser <{parser.__class__.__name__}> requires a single annotation file')
        with open(box_file, parser.read_mode) as f:
            data = parser.deserialize(f.read())

        # Offset
        if offset > 0:
            keys = sorted(list(data.keys()))
            while offset > 0:
                offset -= 1
                del data[keys[offset]]