Introduction

Hello everyone! In this article, I’ll talk about Huawei’s HarmonyOS NEXT. It comes with VisionKit, a powerful tool that lets developers use AI-powered visual features. Here, I’ll focus on the Face Liveness Detection (interactiveLiveness) feature and explain how to integrate it into an app with examples.

What is Face Liveness Detection?

Face Liveness Detection is a technology used to distinguish real human faces from fake ones (like photos, videos, or masks) through a device’s camera. In HarmonyOS NEXT, this feature verifies authenticity by asking users to perform interactive actions, such as blinking or nodding their head.

Use Cases

Attendance tracking systems
Secure app logins (identity verification)
Fake user detection
ID verification support

Development Steps

1. Add Required Module & Permissions

import { interactiveLiveness } from '@kit.VisionKit';
import { common, abilityAccessCtrl, Permissions } from '@kit.AbilityKit';

Add camera permission to your module.json5 file.

"requestPermissions":[
  {
    "name": "ohos.permission.CAMERA",
    "reason": "$string:camera_desc",
    "usedScene": {"abilities": []}
  }
  ]

2. Design the User Interface

@State routeMode: string = "replace";
@State actionsNum: number = 3;

Radio({ value: "replace", group: "routeMode" }).checked(true)
Radio({ value: "back", group: "routeMode" }).checked(false)

TextInput({ placeholder: "Enter 3 or 4" }).type(InputType.Number)

3. Add a Start Button

Button("Start detection")
  .onClick(() => {
    this.startDetection();
  })

4. Handle Permissions & Setup

private startDetection() {
  abilityAccessCtrl.createAtManager().requestPermissionsFromUser(this.context, this.array).then((res) => {
    if (res.permissions[0] === "ohos.permission.CAMERA" && res.authResults[0] === 0) {
      this.runLivenessDetection();
    }
  })
}

5. Start Liveness Detection

private runLivenessDetection() {
  let config = {
    isSilentMode: "INTERACTIVE_MODE",
    routeMode: this.routeMode,
    actionsNum: this.actionsNum
  }

  interactiveLiveness.startLivenessDetection(config).then((success) => {
    if (success) {
      this.getDetectionResult();
    }
  }).catch((err) => {
    console.error("Detection failed", err);
  });
}

6. Get the Result

private getDetectionResult() {
  interactiveLiveness.getInteractiveLivenessResult().then(result => {
    console.log("Liveness type:", result.livenessType);
  }).catch(err => {
    console.error("Failed to get result:", err);
  });
}

About the APIs

The interactiveLiveness module provides the following key functionalities for implementing face liveness detection:

startLivenessDetection(config: InteractiveLivenessConfig): Promise
Launches the face liveness detection screen using the provided configuration. The result of the redirection (success or failure) is returned as a Promise.

getInteractiveLivenessResult(): Promise
Retrieves the result of the liveness detection asynchronously. The returned result includes the detection mode, the best image captured, and optionally a secured buffer and certificate chain (for image security verification scenarios).

InteractiveLivenessConfig
A configuration object that allows you to customize the liveness detection behavior. It includes parameters such as:

isSilentMode: Defines the detection mode. Only INTERACTIVE_MODE is currently supported.
actionsNum: Specifies how many user actions (like blinking, nodding, etc.) will be randomly selected for detection. Only 3 or 4 actions are supported.
routeMode: Determines how the app navigates after detection, using either REPLACE_MODE or BACK_MODE.
successfulRouteUrl / failedRouteUrl: Optional paths to navigate after success or failure.
Additional options such as challenge (for security scenarios), speechSwitch (voice guidance), and isPrivacyMode (requires permission).

Enum Types for Configuration:

DetectionMode: Defines the detection method. Currently, only INTERACTIVE_MODE is available.
ActionsNumber: Specifies the number of required actions (3 or 4).
RouteRedirectionMode: Controls routing behavior after detection (BACK_MODE or REPLACE_MODE).

For full details, check the official API documentation.

Conclusion

The interactiveLiveness feature offered by VisionKit provides significant advantages for user verification and preventing fake face attacks in your HarmonyOS applications. It’s easy to use, runs on-device, and responds very quickly according to device performance.

If you’re developing a security-focused application or just want to add a user verification layer, this feature is perfect for you.

References

Face Liveness Detection

Written by Baris Tuzemen

This content originally appeared on DEV Community and was authored by HarmonyOS