def resolve_image_exif(self, image_url):
        """
        Get the EXIF metadata about an image URL as :class:`OcrdExif`

        Args:
            image_url (string) : URL of image

        Return
            :class:`OcrdExif`
        """
        files = self.mets.find_files(url=image_url)
        if files:
            image_filename = self.download_file(files[0]).local_filename
        else:
            image_filename = self.download_url(image_url)

        if image_url not in self.image_cache['exif']:
            self.image_cache['exif'][image_url] = OcrdExif(Image.open(image_filename))
        return self.image_cache['exif'][image_url]
Get the EXIF metadata about an image URL as :class:`OcrdExif`

        Args:
            image_url (string) : URL of image

        Return
            :class:`OcrdExif`