import json


def json_description(shape, **metadata):
    """Return JSON image description from data shape and other meta data.

    Return UTF-8 encoded JSON.

    >>> json_description((256, 256, 3), axes='YXS')  # doctest: +SKIP
    b'{"shape": [256, 256, 3], "axes": "YXS"}'

    """
    metadata.update(shape=shape)
    return json.dumps(metadata)