Support Center
Under Settings / Facial Recognition you will see the following settings:
Each of these individual settings is explained below.
With this setting turned on, NoahFace constantly scans for faces, and if it sees one, it will attempt to recognise it (ie: compare it with all its known faces). If you turn this setting off, you must first touch the screen before NoahFace will scan for faces.
The default is on. You should consider turning this setting off only if you are mounting NoahFace in a busy thoroughfare, and you don’t want it recognising faces that are passing by.
With this setting turned on, NoahFace will recognise faces at up to a 30 degree angle. With this setting tuned off, NoahFace will only recognise faces that are directly facing the iPad screen.
The default is off, which minimises the chances of an incorrect recognition (aka ‘false positive’). You should consider turning this setting on if people cannot easily directly face the iPad screen due to its mounting location.
The detection threshold controls the process of finding faces in the video. If it is set to Very Low, if something in the image looks like it could be a face, it starts analysing it.
If it is set to Very High, it needs to be extremely clear that it looks like a face before it will start analysing it.
The default is Medium, which should work well in almost all cases.
You should consider changing this to Low if:
You generally should not change this setting to Very Low – if you find you need this setting at Very Low to detect anyone, you should instead consider adjusting the camera brightness, physical shading, or installing front lighting.
You should consider changing this to High, Very High, or Maximum if:
This setting controls the distance at which the NoahFace App will recognise faces. As per the diagram below, this ranges from ‘Very Near’, which requires you to stand approximately 60cm from the iPad, to ‘Very Far’, which will detect faces as far away as 1.8 metres.
The default is Near, which will detect faces at approximately 90 cm.
You should consider changing this to Very Near if:
You should note that if you set this to Very Near and your iPad is mounted vertically, it may be difficult for extremely tall or extremely short people to get their faces in camera view.
You should consider changing this to Far or Very Far if:
With this setting turned on, NoahFace will draw a box around faces on the video screen.
An image of the user’s face is automatically clipped and stored with each event.
The options available are as follows:
Once a face is detected, NoahFace compares the face with all the faces of known individuals. This setting controls how confident the software needs to be that a particular face is a known individual before declaring it a match.
When most people hear about this threshold, their immediate response is that they want it set for absolute certainty. Unfortunately, this is not possible: there is a direct tradeoff between recognition rates and the chances of making a mistake. You should instead think of the Matching Threshold using a graph such as the following:
Note that this is no different from human recognition of faces. If you were to look at 1000 images containing faces of people you knew, and had to always declare who each image was, there would be some images where you could not be absolutely certain (eg: because the images were blurry or the person had their face turned to the side), and you could make mistakes. If you are allowed to pass on 20 images, the chances of you making a mistake are less than if you are only allowed to pass on 1 image. The only way to guarantee you never make a mistake is to pass on all images (which means you will achieve a 0% recognition rate).
The default setting of Medium is an extremely strong setting, and provides the right balance between excellent recognition and minimal chances of making a mistake in the vast majority of environments.
You should consider changing this to High, Very High, or Maximum if:
Biometric learning is the process of capturing and saving multiple sets of biometrics for the same person. These might be extracted at different distances, different angles, or in different lighting conditions, allowing NoahFace can achieve better recognition results.
NoahFace has three different biometric learning modes as follows:
You should consider changing the Learning Mode to Registration or Limited if:
NoahFace also allows you to change the Learning Threshold, which is how certain it needs to be that a face belongs to a known person before additional biometrics are captured. The default is Medium.
You should consider changing the Learning Threshold to High, Very High, or Maximum if:
Once a match is determined, the NoahFace App will display the appropriate action screen – for example a Clock In/Out screen. If an individual has been incorrectly matched, they can press the ‘Not Me’ button so that the biometrics for the matched user are corrected. If you want to hide the ‘Not Me’ button, you can turn off this switch.
