If you find that the Anti-spoofing (liveness) is not working well, check the light pattern emitted by the structured light projector (SLP) by changing video preview on SAFR SCAN Web Console to "Structured Light" and viewing the pattern of dots that are projected on the surrounding objects.  If the pattern is weak as shown below, you may have debris obstructing the structured light projector.

Evaluation

Below (left) is an example of such an obstruction compared to unobstructed emitter (right):


Obstructed SLPUnobstructed SLP (Normal)


Observe that the dot pattern on the left is weak while the dot pattern on the right (good unit) is well defined.  This above example was the result of a very small ant getting inside the unit (attracted by the heat) and stuck on the SLP.


Obstruction of the SLP may be either on the surface of the glass or inside the unit as in above example.  To determine if the SLP is obstructed, take a picture with your phone and view the photo.  Below is a picture of an obstructed SLP (right) and a good SLP (left).

Obstructed SLPUnobstructed SLP (Normal)


In this example, a small ant has become lodged on top of the SLP.  So in this case the obstruction was on the inside of the unit.  In normal case, you should be able to clearly see the SLP shape as shown on the right.

Resolution

If obstruction is believed to be on the glass surface, then attempt to clean the glass with a soft rag, taking care not to scratch the surface.  If the glass is scratched, then the unit may need to be replaced.


If obstruction is on the inside, then there are two possible resolutions.

1. Try to dislodge the debris by tapping the unit.  Be aware that If too much shock is applied, it may damage the unit.  The most likely result of a shock would be to dislodge the SLP which can be fixed by recalibration (recalibration is a detailed process and requires special environment setup - if this is required please consult SAFR Support Team).

2. If option 1 does not result i n clearing the obstruction, then the unit will have to be dissembled and use either forced air or a thin dental pick to clear the debris.  If this is required please consult SAFR Support team for guidance.