Create image object from JSON document retrieved from database.

        Parameters
        ----------
        document : JSON
            Json document in database

        Returns
        -------
        ImageHandle
            Handle for image object

def from_dict(self, document):
        """Create image object from JSON document retrieved from database.

        Parameters
        ----------
        document : JSON
            Json document in database

        Returns
        -------
        ImageHandle
            Handle for image object
        """
        # Get object properties from Json document
        identifier = str(document['_id'])
        active = document['active']
        timestamp = datetime.datetime.strptime(document['timestamp'], '%Y-%m-%dT%H:%M:%S.%f')
        properties = document['properties']
        # The directory is not materilaized in database to allow moving the
        # base directory without having to update the database.
        directory = self.get_directory(identifier)
        # Cretae image handle
        return ImageHandle(identifier, properties, directory, timestamp=timestamp, is_active=active)