使用Google Vision API检测眨眼

Question

我正在使用视觉API进行人脸检测,现在我想实现眨眼,但是当一只眼睛熄灭时,仍然可以通过视觉api检测眼睛.

请帮我看看如何实现眨眼功能.

Answer 1

来自面部的"眼睛开放概率"值是检测眨眼的关键.此外,您可以使用跟踪器跟踪眼睛状态随时间的变化,以检测指示闪烁的事件序列:

双眼睁开 - >双眼闭上 - >双眼睁开

这是一个示例跟踪器:

public class BlinkTracker extends Tracker<Face> {
  private final float OPEN_THRESHOLD = 0.85;
  private final float CLOSE_THRESHOLD = 0.15;

  private int state = 0;

  public void onUpdate(Detector.Detections<Face> detections, Face face) {
    float left = face.getIsLeftEyeOpenProbability();
    float right = face.getIsRightEyeOpenProbability();
    if ((left == Face.UNCOMPUTED_PROBABILITY) ||
        (right == Face.UNCOMPUTED_PROBABILITY)) {
      // At least one of the eyes was not detected.
      return;
    }

    switch (state) {
      case 0:
        if ((left > OPEN_THRESHOLD) && (right > OPEN_THRESHOLD)) {
          // Both eyes are initially open
          state = 1;
        }
        break;

        case 1:
          if ((left < CLOSE_THRESHOLD) && (right < CLOSE_THRESHOLD)) {
            // Both eyes become closed
            state = 2;
          }
          break;

        case 2:
          if ((left > OPEN_THRESHOLD) && (right > OPEN_THRESHOLD)) {
            // Both eyes are open again
            Log.i("BlinkTracker", "blink occurred!");
            state = 0;
          }
        break;
    }
  }

}

请注意,您还需要启用"分类"以使探测器指示眼睛是否打开/关闭:

FaceDetector detector = new FaceDetector.Builder(context)
    .setClassificationType(FaceDetector.ALL_CLASSIFICATIONS)
    .build();

然后将跟踪器添加为处理器,用于随时间从检测器接收面部更新.例如,此配置将用于跟踪视图中最大的面是否闪烁:

detector.setProcessor(
    new LargestFaceFocusingProcessor(detector, new BlinkTracker()));

或者,如果您有兴趣检测所有面(不仅是最大面)的闪烁,则可以使用MultiProcessor而不是LargestFaceFocusingProcessor.