# 人脸活体检测

#### 场景介绍

人脸活体检测支持动作活体检测模式。

动作活体检测支持实时捕捉人脸，需要用户配合做指定动作就可以判断是真实活体，还是非活体攻击（比如：打印图片、人脸翻拍视频以及人脸面具等）。

活体检测是一项纯端侧算法、试用期免费的系统基础服务，推荐开发者使用在考勤打卡、辅助登录和实名认证等低危业务场景中。活体检测减少动作数量或者指定特定动作会降低其安全性，增加被攻破的风险。

端侧算法在HarmonyOS NEXT/5.0.x已完成权威机构（CFCA）检测认证。鉴于支付和金融应用的高风险性，建议开发者基于现有的安全性，针对不同的功能场景进行风险评估和风控策略评估，并采取必要的安全措施。

**图1** 权威认证**增强级**检测报告

**图2** 活体检测示意图

#### 约束与限制

*   平板仅支持竖屏检测，大折叠屏仅支持折叠时使用，小折叠屏仅支持展开时使用。
    
*   支持的文本语种类型：简体中文、繁体中文、英文、维吾尔文、藏文。
    
*   支持的播报语种类型：简体中文、英文。
    
*   人脸活体检测服务暂不支持横屏、分屏进行检测。
    

#### 接口说明

以下仅列出demo中调用的部分主要接口，具体API说明详见API参考。

| 接口名 | 描述 |
| --- | --- |
| startLivenessDetection(config: InteractiveLivenessConfig): Promise<boolean> | 跳转到人脸活体检测页面的入口 |
| getInteractiveLivenessResult(): Promise<InteractiveLivenessResult> | 获取人脸活体检测的结果。使用Promise异步回调 |

#### 开发步骤

1.  将实现人脸活体检测相关的类添加至工程。
    
    ```
    import { common, abilityAccessCtrl, Permissions } from '@kit.AbilityKit';
    import { interactiveLiveness } from '@kit.VisionKit';
    import { BusinessError } from '@kit.BasicServicesKit';
    import { hilog } from '@kit.PerformanceAnalysisKit';
    ```
    
2.  在module.json5文件中添加CAMERA权限，其中reason，abilities标签必填，配置方式参见requestPermissions标签说明。
    
    ```
    "requestPermissions":[
      {
        "name": "ohos.permission.CAMERA",
        "reason": "$string:camera_desc",
        "usedScene": {"abilities": []}
      }
    ]
    ```
    
3.  简单配置页面的布局，选择人脸活体检测验证完后的跳转模式。如果使用back跳转模式，表示人脸活体检测完成后返回到上一页。如果使用replace跳转模式，表示人脸活体检测完跳转到成功或失败页面。默认选择的是replace跳转模式。
    
    ```
    Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
      Text('验证完的跳转模式：')
        .fontSize(18)
        .width('25%')
      Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
        Row() {
          Radio({ value: 'replace', group: 'routeMode' }).checked(true)
            .height(24)
            .width(24)
            .onChange((isChecked: boolean) => {
              this.routeMode = 'replace';
            })
          Text('replace')
            .fontSize(16)
        }
        .margin({ right: 15 })
    
        Row() {
          Radio({ value: 'back', group: 'routeMode' }).checked(false)
            .height(24)
            .width(24)
            .onChange((isChecked: boolean) => {
              this.routeMode = 'back';
            })
          Text('back')
            .fontSize(16)
        }
      }
      .width('75%')
    }
    ```
    
4.  如果选择动作活体模式，可填写验证的动作个数。
    
    ```
    Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
      Text('动作数量：')
        .fontSize(18)
        .width('25%')
      TextInput({
        placeholder: this.actionsNum != 0 ? this.actionsNum.toString() : '动作数量为3或4个'
      })
        .type(InputType.Number)
        .placeholderFont({
          size: 18,
          weight: FontWeight.Normal,
          family: 'HarmonyHeiTi',
          style: FontStyle.Normal
        })
        .fontSize(18)
        .fontWeight(FontWeight.Bold)
        .fontFamily('HarmonyHeiTi')
        .fontStyle(FontStyle.Normal)
        .width('65%')
        .onChange((value: string) => {
          this.actionsNum = Number(value) as interactiveLiveness.ActionsNumber;
        })
    }
    ```
    
5.  点击“开始检测”按钮，触发点击事件。
    
    ```
    Button('开始检测', { type: ButtonType.Normal, stateEffect: true })
      .width(192)
      .height(40)
      .fontSize(16)
      .backgroundColor(0x317aff)
      .borderRadius(20)
      .margin({
        bottom: 56
      })
      .onClick(() => {
        this.startDetection();
      })
    ```
    
6.  触发CAMERA权限校验。
    
    ```
    private context: common.UIAbilityContext = this.getUIContext()?.getHostContext() as common.UIAbilityContext;
    private array: Array<Permissions> = ['ohos.permission.CAMERA'];
    // 校验CAMERA权限
    private startDetection() {
      abilityAccessCtrl.createAtManager().requestPermissionsFromUser(this.context, this.array).then((res) => {
        for (let i = 0; i < res.permissions.length; i++) {
          if (res.permissions[i] === 'ohos.permission.CAMERA' && res.authResults[i] === 0) {
            this.routerLibrary();
          }
        }
      }).catch((err: BusinessError) => {
        hilog.error(0x0001, 'LivenessCollectionIndex', `Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`);
      });
    }
    ```
    
7.  配置人脸活体检测控件的配置项InteractiveLivenessConfig，用于跳转到人脸活体检测控件。
    
    配置中具体的参数可参考API文档。
    
    ```
    let routerOptions: interactiveLiveness.InteractiveLivenessConfig = {
      isSilentMode: this.isSilentMode as interactiveLiveness.DetectionMode,
      routeMode: this.routeMode as interactiveLiveness.RouteRedirectionMode,
      actionsNum: this.actionsNum
    };
    ```
    
8.  调用interactiveLiveness的startLivenessDetection接口，判断跳转到人脸活体检测控件是否成功。
    
    ```
    private routerLibrary() {
      if (canIUse('SystemCapability.AI.Component.LivenessDetect')) {
        interactiveLiveness.startLivenessDetection(routerOptions).then((isSuccess) => {
          if (isSuccess) {
             hilog.info(0x0001, 'LivenessCollectionIndex', `Succeeded in jumping.`);
           } else {
             hilog.info(0x0001, 'LivenessCollectionIndex', `Redirection failed.`);
           }
        }).catch((err: BusinessError) => {
          hilog.error(0x0001, 'LivenessCollectionIndex', `Failed to jump. Code: ${err.code}, message: ${err.message}`);
        });
      } else {
        hilog.error(0x0001, 'LivenessCollectionIndex', 'this api is not supported on this device');
      }
    }
    ```
    
9.  检测结束后回到当前界面，可调用interactiveLiveness的getInteractiveLivenessResult接口，验证人脸活体检测的结果。
    
    ```
    // 获取验证结果
    private getDetectionResultInfo() {
      // getInteractiveLivenessResult接口调用完会释放资源
      if (canIUse('SystemCapability.AI.Component.LivenessDetect')) {
        let resultInfo = interactiveLiveness.getInteractiveLivenessResult();
        resultInfo.then(data => {
          this.resultInfo = data;
        }).catch((err: BusinessError) => {
          this.failResult = {
            'code': err.code,
            'message': err.message
          };
        });
      } else {
        hilog.error(0x0001, 'LivenessCollectionIndex', 'this api is not supported on this device');
      }
    }
    ```
    

#### 开发实例

#### Index.ets

```
import { common, abilityAccessCtrl, Permissions } from '@kit.AbilityKit';
import { interactiveLiveness } from '@kit.VisionKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { hilog } from '@kit.PerformanceAnalysisKit';

@Entry
@Component
struct LivenessCollectionIndex{
  private context: common.UIAbilityContext = this.getUIContext().getHostContext() as common.UIAbilityContext;
  private array: Array<Permissions> = ['ohos.permission.CAMERA'];
  @State actionsNum: number = 0;
  @State isSilentMode: string = 'INTERACTIVE_MODE';
  @State routeMode: string = 'replace';
  @State resultInfo: interactiveLiveness.InteractiveLivenessResult = {
    livenessType: 0
  };
  @State failResult: Record<string, number | string> = {
    'code': 1008302000,
    'message': ''
  };

  build() {
    Stack({
      alignContent: Alignment.Top
    }) {
      Column() {
        Row() {
          Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
            Text('验证完的跳转模式：')
              .fontSize(18)
              .width('25%')
            Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
              Row() {
                Radio({ value: 'replace', group: 'routeMode' }).checked(true)
                  .height(24)
                  .width(24)
                  .onChange(() => {
                    this.routeMode = 'replace';
                  })
                Text('replace')
                  .fontSize(16)
              }
              .margin({ right: 15 })

              Row() {
                Radio({ value: 'back', group: 'routeMode' }).checked(false)
                  .height(24)
                  .width(24)
                  .onChange(() => {
                    this.routeMode = 'back';
                  })
                Text('back')
                  .fontSize(16)
              }
            }
            .width('75%')
          }
        }
        .margin({ bottom: 30 })

          Row() {
            Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start, alignItems: ItemAlign.Center }) {
              Text('动作数量：')
                .fontSize(18)
                .width('25%')
              TextInput({
                placeholder: this.actionsNum != 0 ? this.actionsNum.toString() : '动作数量为3或4个'
              })
                .type(InputType.Number)
                .placeholderFont({
                  size: 18,
                  weight: FontWeight.Normal,
                  family: 'HarmonyHeiTi',
                  style: FontStyle.Normal
                })
                .fontSize(18)
                .fontWeight(FontWeight.Bold)
                .fontFamily('HarmonyHeiTi')
                .fontStyle(FontStyle.Normal)
                .width('65%')
                .onChange((value: string) => {
                  this.actionsNum = Number(value) as interactiveLiveness.ActionsNumber;
                })
            }
          }
      }
      .margin({ left: 24, top: 80 })
      .zIndex(1)

      Stack({
        alignContent: Alignment.Bottom
      }) {
        if (this.resultInfo?.mPixelMap) {
          Image(this.resultInfo?.mPixelMap)
            .width(260)
            .height(260)
            .align(Alignment.Center)
            .margin({ bottom: 260 })
          Circle()
            .width(300)
            .height(300)
            .fillOpacity(0)
            .strokeWidth(60)
            .stroke(Color.White)
            .margin({ bottom: 250, left: 0 })
        }

        Text(this.resultInfo.mPixelMap ?
          '检测成功' :
          this.failResult.code != 1008302000 ?
            '检测失败' :
            '')
          .width('100%')
          .height(26)
          .fontSize(20)
          .fontColor('#000000')
          .fontFamily('HarmonyHeiTi')
          .margin({ top: 50 })
          .textAlign(TextAlign.Center)
          .fontWeight('Medium')
          .margin({ bottom: 240 })

        if (this.failResult.code != 1008302000) {
          Text(this.failResult.message as string)
            .width('100%')
            .height(26)
            .fontSize(16)
            .fontColor(Color.Gray)
            .textAlign(TextAlign.Center)
            .fontFamily('HarmonyHeiTi')
            .fontWeight('Medium')
            .margin({ bottom: 200 })
        }

        Button('开始检测', { type: ButtonType.Normal, stateEffect: true })
          .width(192)
          .height(40)
          .fontSize(16)
          .backgroundColor(0x317aff)
          .borderRadius(20)
          .margin({
            bottom: 56
          })
          .onClick(() => {
            this.startDetection();
          })
      }
      .height('100%')
    }
  }

  onPageShow() {
    this.resultRelease();
    this.getDetectionResultInfo();
  }

  // 配置人脸活体检测参数并调用检测接口
  private routerLibrary() {
    let routerOptions: interactiveLiveness.InteractiveLivenessConfig = {
      isSilentMode: this.isSilentMode as interactiveLiveness.DetectionMode,
      routeMode: this.routeMode as interactiveLiveness.RouteRedirectionMode,
      actionsNum: this.actionsNum
    };

    if (canIUse('SystemCapability.AI.Component.LivenessDetect')) {
      interactiveLiveness.startLivenessDetection(routerOptions).then((isSuccess) => {
        if (isSuccess) {
            hilog.info(0x0001, 'LivenessCollectionIndex', `Succeeded in jumping.`);
          } else {
            hilog.info(0x0001, 'LivenessCollectionIndex', `Redirection failed.`);
          }
      }).catch((err: BusinessError) => {
        hilog.error(0x0001, 'LivenessCollectionIndex', `Failed to jump. Code: ${err.code}, message: ${err.message}`);
      });
    } else {
      hilog.error(0x0001, 'LivenessCollectionIndex', 'this api is not supported on this device');
    }
  }

  // 校验CAMERA权限
  private startDetection() {
    abilityAccessCtrl.createAtManager().requestPermissionsFromUser(this.context, this.array).then((res) => {
      for (let i = 0; i < res.permissions.length; i++) {
        if (res.permissions[i] === 'ohos.permission.CAMERA' && res.authResults[i] === 0) {
        this.routerLibrary();
      }
     }
    }).catch((err: BusinessError) => {
      hilog.error(0x0001, 'LivenessCollectionIndex', `Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`);
    });
  }

  // 获取验证结果
  private getDetectionResultInfo() {
    // getInteractiveLivenessResult接口调用完会释放资源
    if (canIUse('SystemCapability.AI.Component.LivenessDetect')) {
      interactiveLiveness.getInteractiveLivenessResult().then(data => {
        this.resultInfo = data;
      }).catch((err: BusinessError) => {
        this.failResult = {
          'code': err.code,
          'message': err.message
        };
      });
    } else {
      hilog.error(0x0001, 'LivenessCollectionIndex', 'this api is not supported on this device');
    }
  }

  // result release
  private resultRelease() {
    this.resultInfo = {
      livenessType: 0
    };
    this.failResult = {
      'code': 1008302000,
      'message': ''
    };
  }
}
```