MLKit Firebase android-如何将FirebaseVisionFace转换为图像对象（如位图）？

我已经将MLkit FaceDetection集成到了我的android应用程序中。我在下面提到了网址

https://firebase.google.com/docs/ml-kit/android/detect-faces

面部检测处理器类别的代码为

import java.io.IOException;
import java.util.List;

/** Face Detector Demo. */
public class FaceDetectionProcessor extends VisionProcessorBase<List<FirebaseVisionFace>> {

  private static final String TAG = "FaceDetectionProcessor";

  private final FirebaseVisionFaceDetector detector;

  public FaceDetectionProcessor() {

    FirebaseVisionFaceDetectorOptions options =
        new FirebaseVisionFaceDetectorOptions.Builder()
            .setClassificationType(FirebaseVisionFaceDetectorOptions.ALL_CLASSIFICATIONS)
            .setLandmarkType(FirebaseVisionFaceDetectorOptions.ALL_LANDMARKS)
            .setTrackingEnabled(true)
            .build();

    detector = FirebaseVision.getInstance().getVisionFaceDetector(options);
  }

  @Override
  public void stop() {
    try {
      detector.close();
    } catch (IOException e) {
      Log.e(TAG, "Exception thrown while trying to close Face Detector: " + e);
    }
  }

  @Override
  protected Task<List<FirebaseVisionFace>> detectInImage(FirebaseVisionImage image) {
    return detector.detectInImage(image);
  }

  @Override
  protected void onSuccess(
      @NonNull List<FirebaseVisionFace> faces,
      @NonNull FrameMetadata frameMetadata,
      @NonNull GraphicOverlay graphicOverlay) {
      graphicOverlay.clear();

    for (int i = 0; i < faces.size(); ++i) {
      FirebaseVisionFace face = faces.get(i);
      FaceGraphic faceGraphic = new FaceGraphic(graphicOverlay);
      graphicOverlay.add(faceGraphic);
      faceGraphic.updateFace(face, frameMetadata.getCameraFacing());
    }




  }

  @Override
  protected void onFailure(@NonNull Exception e) {
    Log.e(TAG, "Face detection failed " + e);
  }
}

在“ onSuccess”侦听器中，我们将获得“ FirebaseVisionFace”类对象的数组，这些对象将具有“ Bounding Box”的面孔。

@Override
      protected void onSuccess(
          @NonNull List<FirebaseVisionFace> faces,
          @NonNull FrameMetadata frameMetadata,
          @NonNull GraphicOverlay graphicOverlay) {
          graphicOverlay.clear();

        for (int i = 0; i < faces.size(); ++i) {
          FirebaseVisionFace face = faces.get(i);
          FaceGraphic faceGraphic = new FaceGraphic(graphicOverlay);
          graphicOverlay.add(faceGraphic);
          faceGraphic.updateFace(face, frameMetadata.getCameraFacing());
        }
      }

我想知道如何将此FirebaseVisionFace对象转换为Bitmap。我想提取人脸图像并在ImageView中显示它。谁能帮帮我吗 。提前致谢。

注意：我已经从以下网址下载了MLKit android的示例源代码

https://github.com/firebase/quickstart-android/tree/master/mlkit