Hi Alf,
Long time no see. I completely agree with you: one have to separate FaceReco for Access control and FaceReco for Blacklisting users (Stadium, Retail, Airport, ..)
John,
Regarding Face recognition technology, its' true that its Performance and Consistency and its Price has not yet reached the ones of the best leader in Biometrics for access control => 2D Fingerprint. It is widely known by specialists that ~95% of the Biometric readers that were shipped in 2017 are ... Fingerprint readers. Then Face then Iris then the other HandShape/Fingerpvein/HandVein and other methods fill in the remaining 5%. Maybe that number will be 94% or 92% in 2018. But that does not change the big picture.
If you want to confirm that ... I advice that you purchase IHS Markit report (access control) at least one time. I believe it gives a reliable trend based on major manufacturers globally.
https://technology.ihs.com/Categories/450443/access-control-fire
I believe that FaceReco for Blacklising users is the field of CCTV HW/SW manufacturers (Axis, Genetec, Milestone, Hik, ..), and I have no expertise to share on that field.
FaceReco for Access Control is very different. Here, you have to consider two cases:
A- Very high secure areas (Data-Center, Gov, Airport) => in that case most user hold a credential (DesFire EV1 or HID iClass or HID Seos or Passport, Nat_ID_Card). So it is quite easy to process a "card then face" 1:1 (verification matching) with very high hit rate for that use case. Note that at Suprema Inc, we use FaceStation2 (Infrared sensing technology). That is a 2D technology based on ~30x Infrared templates (including evolution templates). The only limitation so far is that Face templates cannot be stored on Smart Card due to size + need for evolution (because your face changes .. look at your pics from 5 years ago ^^). Note that Suprema FaceStation2 has this face change machine learning + supports most Cards (EM, HID Prox, Mifare/DesFire EV1, iClass SE, Seos, NFC, BLE) + all formats (I mean the wiegands 25~64 bits) + HID/AES/DES Encryption (for the Secure ID).
B- Bio-Secure Areas that need FaceOnly recognition. Here the end-user request is "I want security AND convenience". That means users wish not to use cards at all and no contact skin contact at all (that's a fair request in some cases). So what is requested here is a 1:N (one to many) face matching. For that use case Suprema limits the faces to 3K users. Not because of a problem of device memory size, but because we have found out that real FAR/FRR (false acceptance / false rejection rates) and matching time are only acceptable up to that point. I insist on real FAR/FRR because you sometimes can find FAR/FRR in bio-devices specs and that is a biggest "BS" ever made by Bio-manufacturers: FAR/FRR given are theoretical (not based on real faces but just mathematics values based on algorithm). True thing is that Real FAR/FRR will depend on face chances (makeup, hairs, beard, environment, tiredness, gained/lost weight, face attitude/smile_or_not), Face Subject Angle (and here for Disablities Act), DB size (100 users or 2000 users?) and some other factors that shall remain confidential.
As a sum up:
Based on 4 years of installation of FaceStation and FaceStation2, I am very confident with A- case above with unlimited users (=1 million) and B-Case up to 3,000 Faces (one user can have two/multiple faces = with/without glasses).
One point in John discussion above: CPU processing power plays for a lot in performance because it allows to make use of heavier Algorithms/tricks. Here in FaceStation2, Suprema uses a 1.4Ghz Quad-Core.