'Returns metadata about an image in the HTTP headers of the
response object
:param req: The WSGI/Webob Request object
:param id: The opaque image identifier
:returns: similar to \'show\' method but without image_data
:raises HTTPNotFound: if image metadata is not available to user'

def meta(self, req, id):

    self._enforce(req, 'get_image')
    image_meta = self.get_image_meta_or_404(req, id)
    image_meta = redact_loc(image_meta)
    self._enforce_read_protected_props(image_meta, req)
    return {'image_meta': image_meta}
