from typing import Mapping


def _extract_description(metadata: Mapping[str, str]) -> str:
    """
       Extract description from image file.

       :param metadata: Extracted meta-data from file.
       :return: The description
    """
    description = ""
    description = metadata.get("IPTC:Headline", description)
    description = metadata.get("EXIF:ImageDescription", description)
    description = metadata.get("IPTC:Caption-Abstract", description)
    description = metadata.get("PNG:Description", description)
    description = metadata.get("XMP:Description", description)
    description = metadata.get("PNG:Comment", description)
    description = metadata.get("File:Comment", description)
    description = metadata.get("Description", description)
    return description