Since the dawn of A.I, facial recognition systems have been evolving rapidly to exceed our expectations at every turn. In a few years’ time you’ll be able to go through the airport basically just using your face. If you have bags to drop off, you’ll be able to use the self-service system and just have your face captured and matched. You’ll then go to security, the same thing happens just use your biometric. The big tech giants have proved this can be done at massive scale. What the world now needs is higher adoption through democratization of this technology, where even small organizations can use this advanced technology with a plug and play solution.
The answer to this is Deep Auth, Signzy’s inhouse facial recognition system. This allows large scale face authentication in real-time, using your everyday mobile device cameras in the real world.
While one to one face match is now very popular (thanks to latest Apple Iphone X), it’s still not easy to authenticate people from larger datasets, that is identifying you from thousands of other images. What is even more challenging is doing this in real-time. And just to add some bit of realism, sending images and videos over mobile internet slows this down even further.
This system can detect and recognise faces at real time in any event, organization, office space without any special device. This makes Deep Auth an ideal candidate to use in real-world scenarios where it might be not possible to deploy large human workforce or spend millions of dollars to monitor people and events. Workplaces, Education Institutes, Bank branches even large residential buildings are all valid areas of use.
Digital journeys can benefit from face based authentication thus eliminating the friction of username, password and adding security of biometrics. There can also be hundreds of other use-cases which hopefully our customers will come up with, and help us improve our tech.
Deep Auth is robust to appearance variations like sporting a beard, or wearing eyeglasses. This is made possible by ensuring that Deep Auth learns the facial features dynamically (Online training) .
Technology
The technology behind face recognition is powered by a series of Convolution Neural Networks(CNN). Let’s divide the tech into two parts :
Face DetectionFace Recognition
Face Detection:
This part involves a 3 stage cascaded CNN network. This is to ensure the face is robustly detected. In the first stage we propose regions (Objectablility score) and their regression boxes . In the second stage, we take these proposed regression boxes as the input and then re-propose them to reduce the number of false positives. Non-maximal suppression is applied after each stage to further reduce the number of false positives.
In the final stage we compute the facial landmarks with 5 point localization for both the eyes, nose and the edges of the mouth. This stage is essential to ensure that the face is aligned before we pass it to the face recognizer. The loss function is an ensemble of the center loss and IoU (Intersection Over Union) loss. We trained the network for 150k iterations on the WIDER Face dataset.
Face Recognition:
The extracted faces are then passed to a siamese network to where we use contrastive loss to converge the network. The siamese network is a 152 layer Resnet where the output is a 512-D vector depicting the encodings of the given face.
We then use K- Nearest Neighbours(KNN) to classify each encodings to the nearest face encodings that was injected to KNN during the training phase. The 512-D vectorization used here compared to 128-D vectorization used in other face recognition systems helps in distinguishing fine details across each face. This provides high accuracy to the system even with a large number of non-discriminative faces. We are also working on extending the siamese network to extract 1024-D face encondings.
Conclusion
Hopefully this blog was able to explain more about Deep Auth and the technology behind it. Ever since UIDAI made face recognition mandatory for Aadhaar authentication, face recognition will start to prevail every nook and corner of the nation for biometric authentication. Thus democratization of face authentication allows even small companies to access this technology within their organizations. This should hopefully allow more fair play and give everyone a chance to use advanced technology to improve their lives and businesses.
About Signzy
Signzy helps financial institutions transform current semi-manual processes into real-time digital systems, using Artificial Intelligence in Banking . This ensures that the new processes are user-friendly, yet secure and compliant. You can reach out to our team at reachout@signzy.com