人脸比对
====

#### 适用场景

输入的两张比对图片是同一个人的照片时，系统返回的比对结果为"同一个人"，置信分数比较高；当两张比对图片不是同一个人的照片时，系统返回的比对结果为"非同一个人"，置信分数很低。可以用于APP中需要用到人脸比对功能的场景，比如娱乐类APP中比较两个人的相似度、与明星的相似度等。

效果如下图所示：

![](https://contentcenter-vali-drcn.dbankcdn.cn/pvt_2/DeveloperAlliance_scene_100_1/ca/v3/-vhIG4r4Q--dc2KgUtLOvg/zh-cn_image_0000002625109123.png?HW-CC-KV=V1&HW-CC-Date=20260612T073759Z&HW-CC-Expire=86400&HW-CC-Sign=F6BED03BA0A4E8093E50A033AD22F80E3C7F7482253C23A766300DCE45B7610B)

#### 开发步骤

1.  在使用人脸比对时，将实现人脸比对相关的类添加至工程。
    
    import { faceComparator } from '@kit.CoreVisionKit';
    import { image } from '@kit.ImageKit';
    import { hilog } from '@kit.PerformanceAnalysisKit';
    import { BusinessError } from '@kit.BasicServicesKit';
    import { fileIo } from '@kit.CoreFileKit';
    import { photoAccessHelper } from '@kit.MediaLibraryKit';
    
2.  初始化和释放：在aboutToAppear中调用[faceComparator.init()](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/core-vision-facecomparator-api#facecomparatorinit)初始化人脸比对分析器（加载模型），在aboutToDisappear中调用[faceComparator.release()](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/core-vision-facecomparator-api#facecomparatorrelease)释放资源。
    
    async aboutToAppear(): Promise<void> {
      const initResult = await faceComparator.init();
      hilog.info(0x0000, TAG, \`Face comparator initialization result:${initResult}\`);
    }
    
    async aboutToDisappear(): Promise<void> {
      await faceComparator.release();
      hilog.info(0x0000, TAG, 'Face comparator released successfully');
    }
    
3.  通过photoAccessHelper.PhotoViewPicker拉起图库选择两张待比对的图片，使用fileIo与image模块将URI转换为[PixelMap](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/arkts-apis-image-pixelmap)，为后续比对接口准备输入数据。
    
    Button('选择图片')
      .type(ButtonType.Capsule)
      .fontColor(Color.White)
      .alignSelf(ItemAlign.Center)
      .width('80%')
      .margin(10)
      .onClick(() => {
        // 拉起图库，获取图片资源
        void this.selectImage();
      })
    
    选择图片与解码图片的方法实现如下：
    
    private async selectImage() {
      let uri = await this.openPhoto();
      if (uri === undefined) {
        hilog.error(0x0000, TAG, 'Failed to get two image uris.');
        return;
      }
      this.loadImage(uri);
    }
    
    private async openPhoto(): Promise<string\[\]> {
      return new Promise<string\[\]>((resolve, reject) => {
        let photoPicker: photoAccessHelper.PhotoViewPicker = new photoAccessHelper.PhotoViewPicker();
        photoPicker.select({
          MIMEType: photoAccessHelper.PhotoViewMIMETypes.IMAGE\_TYPE,
          maxSelectNumber: 2
        }).then(res => {
          resolve(res.photoUris);
        }).catch((err: BusinessError) => {
          hilog.error(0x0000, TAG, \`Failed to get photo image uris. code: ${err.code}, message: ${err.message}\`);
          reject();
        });
      });
    }
    
    private loadImage(names: string\[\]) {
      setTimeout(async () => {
        let imageSource: image.ImageSource | undefined = undefined;
        let fileSource: fileIo.File;
        fileSource = await fileIo.open(names\[0\], fileIo.OpenMode.READ\_ONLY);
        imageSource = image.createImageSource(fileSource.fd);
        this.chooseImage = await imageSource.createPixelMap();
        fileSource = await fileIo.open(names\[1\], fileIo.OpenMode.READ\_ONLY);
        imageSource = image.createImageSource(fileSource.fd);
        this.chooseImage1 = await imageSource.createPixelMap();
        await fileIo.close(fileSource);
      }, 100);
    }
    
4.  构造[VisionInfo](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/core-vision-facecomparator-api#visioninfo)对象并传入两张图片的PixelMap，调用[faceComparator.compareFaces](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/core-vision-facecomparator-api#facecomparatorcomparefaces)方法，获取相似度分数，并将结果展示在界面上。
    
    Button('人脸比对')
      .type(ButtonType.Capsule)
      .fontColor(Color.White)
      .alignSelf(ItemAlign.Center)
      .width('80%')
      .margin(10)
      .onClick(() => {
        if (!this.chooseImage || !this.chooseImage1) {
          hilog.error(0x0000, TAG, 'Failed to choose image');
          return;
        }
        // 调用人脸比对接口
        let visionInfo: faceComparator.VisionInfo = {
          pixelMap: this.chooseImage
        };
        let visionInfo1: faceComparator.VisionInfo = {
          pixelMap: this.chooseImage1
        };
        faceComparator.compareFaces(visionInfo, visionInfo1)
          .then((data: faceComparator.FaceCompareResult) => {
            let faceString = \`degree of similarity: ${this.toPercentage(data.similarity)}${(data.isSamePerson) ? '. is' : '. no'} same person\`;
            hilog.info(0x0000, TAG, 'faceString data is ' + faceString);
            this.dataValues = faceString;
          })
          .catch((error: BusinessError) => {
            hilog.error(0x0000, TAG, \`Face comparison failed. Code: ${error.code}, message: ${error.message}\`);
            this.dataValues = \`Error: ${error.message}\`;
          });
      })
    
    相似度数值转百分比展示的辅助方法：
    
    private toPercentage(num: number): string {
      return \`${(num \* 100).toFixed(2)}%\`;
    }
    

#### 开发实例

#### \[h2\]Index.ets

import { faceComparator } from '@kit.CoreVisionKit';
import { image } from '@kit.ImageKit';
import { hilog } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { fileIo } from '@kit.CoreFileKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';

const TAG: string = 'FaceCompareSample';

@Entry
@Component
struct Index {
  @State chooseImage: PixelMap | undefined = undefined;
  @State chooseImage1: PixelMap | undefined = undefined;
  @State dataValues: string = '';

  async aboutToAppear(): Promise<void> {
    const initResult = await faceComparator.init();
    hilog.info(0x0000, TAG, \`Face comparator initialization result:${initResult}\`);
  }

  async aboutToDisappear(): Promise<void> {
    await faceComparator.release();
    hilog.info(0x0000, TAG, 'Face comparator released successfully');
  }

  build() {
    Column() {
      Image(this.chooseImage)
        .objectFit(ImageFit.Fill)
        .height('30%')
        .accessibilityDescription('默认图片1')
      Image(this.chooseImage1)
        .objectFit(ImageFit.Fill)
        .height('30%')
        .accessibilityDescription('默认图片2')
      Text(this.dataValues)
        .copyOption(CopyOptions.LocalDevice)
        .height('15%')
        .margin(10)
        .width('60%')
      Button('选择图片')
        .type(ButtonType.Capsule)
        .fontColor(Color.White)
        .alignSelf(ItemAlign.Center)
        .width('80%')
        .margin(10)
        .onClick(() => {
          // 拉起图库
          void this.selectImage();
        })
      Button('人脸比对')
        .type(ButtonType.Capsule)
        .fontColor(Color.White)
        .alignSelf(ItemAlign.Center)
        .width('80%')
        .margin(10)
        .onClick(() => {
          if (!this.chooseImage || !this.chooseImage1) {
            hilog.error(0x0000, TAG, 'Failed to choose image');
            return;
          }
          // 调用人脸比对接口
          let visionInfo: faceComparator.VisionInfo = {
            pixelMap: this.chooseImage
          };
          let visionInfo1: faceComparator.VisionInfo = {
            pixelMap: this.chooseImage1
          };
          faceComparator.compareFaces(visionInfo, visionInfo1)
            .then((data: faceComparator.FaceCompareResult) => {
              let faceString = \`degree of similarity: ${this.toPercentage(data.similarity)}${(data.isSamePerson) ? '. is' : '. no'} same person\`;
              hilog.info(0x0000, TAG, 'faceString data is ' + faceString);
              this.dataValues = faceString;
            })
            .catch((error: BusinessError) => {
              hilog.error(0x0000, TAG, \`Face comparison failed. Code: ${error.code}, message: ${error.message}\`);
              this.dataValues = \`Error: ${error.message}\`;
            });
        })
    }
    .width('100%')
    .height('100%')
    .justifyContent(FlexAlign.Center)
  }

  private toPercentage(num: number): string {
    return \`${(num \* 100).toFixed(2)}%\`;
  }

  private async selectImage() {
    let uri = await this.openPhoto();
    if (uri === undefined) {
      hilog.error(0x0000, TAG, 'Failed to get two image uris.');
      return;
    }
    this.loadImage(uri);
  }

  private async openPhoto(): Promise<string\[\]> {
    return new Promise<string\[\]>((resolve, reject) => {
      let photoPicker: photoAccessHelper.PhotoViewPicker = new photoAccessHelper.PhotoViewPicker();
      photoPicker.select({
        MIMEType: photoAccessHelper.PhotoViewMIMETypes.IMAGE\_TYPE,
        maxSelectNumber: 2
      }).then(res => {
        resolve(res.photoUris);
      }).catch((err: BusinessError) => {
        hilog.error(0x0000, TAG, \`Failed to get photo image uris. code: ${err.code}, message: ${err.message}\`);
        reject();
      });
    });
  }

  private loadImage(names: string\[\]) {
    setTimeout(async () => {
      let imageSource: image.ImageSource | undefined = undefined;
      let fileSource: fileIo.File;
      fileSource = await fileIo.open(names\[0\], fileIo.OpenMode.READ\_ONLY);
      imageSource = image.createImageSource(fileSource.fd);
      this.chooseImage = await imageSource.createPixelMap();
      fileSource = await fileIo.open(names\[1\], fileIo.OpenMode.READ\_ONLY);
      imageSource = image.createImageSource(fileSource.fd);
      this.chooseImage1 = await imageSource.createPixelMap();
      await fileIo.close(fileSource);
    }, 100);
  }
}