getIsLeftEyeOpen 来自移动视觉的概率 API 给出的值为 -1

Question

我正在使用 mobile vision API 中的 getIsLeftEyeOpenProbability 来了解眼睛是否睁开。然而，奇怪的事情发生了，即使睁开眼睛，我总是得到-1的概率。

代码如下：

FaceDetector faceDetector = new FaceDetector.Builder(getApplicationContext())
                                            .setTrackingEnabled(false)
                                            .setLandmarkType(FaceDetector.ALL_LANDMARKS)
                                            .build();

Frame frame = new Frame.Builder().setBitmap(obtainedBitmap).build();
SparseArray < Face > facesForLandmarks = faceDetector.detect(frame);
faceDetector.release();
Thread homeSwipeThread;

for (int a = 0; a < facesForLandmarks.size(); a++) {
    Face thisFace = facesForLandmarks.valueAt(a);
    List < Landmark > landmarks = thisFace.getLandmarks();

    for (int b = 0; b < landmarks.size(); b++) {
        if (landmarks.get(b).getType() == landmarks.get(b).LEFT_EYE) {
            leftEye = new Point(landmarks.get(b).getPosition().x, landmarks.get(b).getPosition().y - 3);
        } else if (landmarks.get(b).getType() == landmarks.get(b).RIGHT_EYE) {
            rightEye = new Point(landmarks.get(b).getPosition().x, landmarks.get(b).getPosition().y - 3);
        } //end else if.
    } //end inner
    //for every detected face check eyes probability:

    if (thisFace.getIsLeftEyeOpenProbability() <= 0.1) {
        //some code
    }
 }

为什么会出现这种情况，我该如何解决？

Answer 1

您缺少用于对眼睛进行分类的检测器选项 open/closed，通过 "setClassificationType"。 faceDetector 应该像这样创建：

FaceDetector faceDetector =
    new FaceDetector.Builder(getApplicationContext())
        .setTrackingEnabled(false)
        .setLandmarkType(FaceDetector.ALL_LANDMARKS)
        .setClassificationType(FaceDetector.ALL_CLASSIFICATIONS)
        .build();

在这种情况下，您可以省略 "setLandmarkType"，因为它是 "setClassificationType" 的隐含依赖项。

此外，即使设置了这个选项，也有可能得到 -1，这是文档中提到的 "UNCOMPUTED_PROBABILITY" 值：

https://developers.google.com/android/reference/com/google/android/gms/vision/face/Face.html#public-methods

返回 UNCOMPUTED_PROBABILITY 通常意味着未检测到眼睛，因此无法确定眼睛是睁着还是闭着。所以我想你想要这个：

float leftOpen = thisFace.getIsLeftEyeOpenProbability();
if ((leftOpen != Face.UNCOMPUTED_PROBABILITY) && (leftOpen <= 0.1)) {
    //some code
}

getIsLeftEyeOpen 来自移动视觉的概率 API 给出的值为 -1

getIsLeftEyeOpenProbability from mobile vision API gives a vlaue of -1

android

computer-vision

android-camera

android-vision

eye-detection