Face Service provides face detection capabilities through the Content Detection API. It includes four functions — facial attribute detection, face comparison, face retrieval, and face liveness detection — to cover common identity and security scenarios.
Features
| Feature | What it answers | Use case | API operations |
|---|---|---|---|
| Facial attribute detection | Is there a face in this image, and what are its attributes? | Detect whether one or more faces appear in an image and analyze expressions or other attributes | Face property detection API |
| Face comparison | Do the faces in these two images belong to the same person? | Attendance check-in scenarios; only one face per detected image is supported | Face comparison and synchronous detection API and face comparison asynchronous detection API |
| Face retrieval | Which individuals in my collection look most like this face? | Access control authentication scenarios, such as security gates | Face retrieval API and face retrieval overview |
| Face liveness detection | Is the face in this image a real person or a spoofed image? | Detect whether a face comes from a retaken photo or other spoofing attempt | — |
Face liveness detection methods
Face liveness detection supports two methods to cover different threat models:
Passive liveness detection: Determines whether the face comes from a retaken or forged image based on a single submitted image. No user interaction is required.
Interactive face liveness detection: Determines whether the face belongs to a live person by analyzing a sequence of images captured during user interaction.
Key concepts
Face
A face is a single face region detected within a submitted image. When Face Service processes an image, it records each detected face along with its position in the image. Multiple faces can be detected in the same image as long as enough facial landmarks are present.
Person
A person represents an individual associated with one or more face images. When you upload a face image, you specify the person it belongs to. Each image associated with a person must contain no more than one face and must depict that same individual.
Face collection
A face collection is a logical group that stores person information for face retrieval. To search for individuals similar to a given face, specify the face collection to search within.