def gen_image_name(reference: str) -> str:
    """
    Generate the image name as a signing input, based on the docker reference.
    Args:
        reference: Docker reference for the signed content,
            e.g. registry.redhat.io/redhat/community-operator-index:v4.9
    """
    no_tag = reference.split(":")[0]
    image_parts = no_tag.split("/")
    return "/".join(image_parts[1:])