AWS S3 Bucket政策公开。如何使对象私有？

I've a bucket with GetObject available to everyone on full bucket(*). I want to make a few objects private(through Object level operation ACL), i.e. only the bucket owner should have read access to the object. I've gone through all available documentation, but couldn't find any possible way. Can anyone confirm is this possible or not?I've a bucket with GetObject available to every