import asyncio
import concurrent.futures

# vips is already multithreaded, but needs to be kicked off the python asyncio thread.
toThreadExecutor = concurrent.futures.ThreadPoolExecutor(max_workers=2, thread_name_prefix="image")

async def to_thread(f):
    loop = asyncio.get_running_loop()
    return await loop.run_in_executor(toThreadExecutor, f)