- Open set identification: it’s a condition where inside of a system we assume that for every identification or verification the person that’s trying to be identified surely is enrolled in the system. Every identification gives a result.
- Closed set identification: in this case, it’s not sure that every individual that’s trying to be identified is actually enrolled in the system, so this can return an error message saying that the user’s not enrolled. In this condition, the system may be wrong and reject a person that’s enrolled.
- Watch list (Black or White list): The system has a list of subjects and checks if they’re allowed or not to access the system. White list contains all the subjects that are allowed to enter the system; Black list contains subjects that are not allowed to enter the system.
Different types of settings
- Controlled: when the user is trying to be identified, the system or an administrator tries to avoid the distortion, in a way to get the best possible results. For example, if the user is recognizing their face, the pose, the illumination, and the expression could be key aspects, and controlling it would give a better result.
- Uncontrolled: it’s the opposite of a controlled environment. It’s the most realistic setting. Samples, and so templates, can have various types of distortions that can affect the results.
Different types of users
- Cooperative: the user is trying to be recognized. That doesn’t mean that the user is not an impostor, since an impostor that’s trying to spoof the system surely wants to be recognized as an authorized person.
- Non-Cooperative: the user is indifferent or adverse to the recognition. An impostor may try to camouflage, in order to not be recognized.
- Private: The users of the systems are customers or employees of the entity that’s installing the system.
- Public: The opposite of private.
- Used/Not used: How frequently the system is used, such as more times per day or a few times per month, etc.
- Aware/Not aware: If the user is aware or not of the recognition process taken by the system.