android - 视频抓拍人脸检测-安卓

Question

为了在视频捕获过程中跟踪/检测人脸。我已经能够捕捉并存储视频。现在我在其中添加人脸检测。我现在正在视频捕获过程中检测人脸。 我如何检查 facedetect 是否正常工作。我可以做哪些改变:

public class AndroidVideoCaptureExample extends Activity {
private Camera mCamera;
private int vWidth, vHeight;
private CameraPreview mPreview;
private MediaRecorder mediaRecorder;
private Button capture, switchCamera;
private Context myContext;
private LinearLayout cameraPreview;
private boolean cameraFront = false;
private int desiredwidth = 640, desiredheight = 360;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

    myContext = this;
    initialize();
}

private int findFrontFacingCamera() {
    int cameraId = -1;
    // Search for the front facing camera
    int numberOfCameras = Camera.getNumberOfCameras();
    for (int i = 0; i < numberOfCameras; i++) {
        CameraInfo info = new CameraInfo();
        Camera.getCameraInfo(i, info);
        if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
            cameraId = i;
            cameraFront = true;
            break;
        }
    }
    return cameraId;
}

public void onResume() {
    super.onResume();
    if (!hasCamera(myContext)) {
        Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG);
        toast.show();
        finish();
    }
    if (mCamera == null) {
        // if the front facing camera does not exist
        if (findFrontFacingCamera() < 0) {
            Toast.makeText(this, "No front facing camera found.", Toast.LENGTH_LONG).show();
            switchCamera.setVisibility(View.GONE);
        }
        mCamera = Camera.open(findFrontFacingCamera());
        mCamera.setFaceDetectionListener(new FaceDetectionListener());
        mCamera.setDisplayOrientation(90);
        mPreview.refreshCamera(mCamera);
        startFaceDetection();
    }
}

public void initialize() {
    cameraPreview = (LinearLayout) findViewById(R.id.camera_preview);

    mPreview = new CameraPreview(myContext, mCamera);
    cameraPreview.addView(mPreview);

    capture = (Button) findViewById(R.id.button_capture);
    capture.setOnClickListener(captrureListener);

}



@Override
protected void onPause() {
    super.onPause();
    // when on Pause, release camera in order to be used from other
    // applications
    releaseCamera();
}

private boolean hasCamera(Context context) {
    // check if the device has camera
    if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {

        return true;
    } else {
        return false;
    }
}

boolean recording = false;
OnClickListener captrureListener = new OnClickListener() {@Override
    public void onClick(View v) {
        if (recording) {
            // stop recording and release camera
            mediaRecorder.stop(); // stop the recording
            releaseMediaRecorder(); // release the MediaRecorder object
            Toast.makeText(AndroidVideoCaptureExample.this, "Video captured!", Toast.LENGTH_LONG).show();

            Toast.makeText(AndroidVideoCaptureExample.this, vWidth + "BY" + vHeight, Toast.LENGTH_LONG).show();

            recording = false;
        } else {
            if (!prepareMediaRecorder()) {
                Toast.makeText(AndroidVideoCaptureExample.this, "Failed in prepareMediaRecorder()!\n - Ended -", Toast.LENGTH_LONG).show();
                finish();
            }
            // work on UiThread for better performance
            runOnUiThread(new Runnable() {
                public void run() {
                    // If there are stories, add them to the table

                    try {
                        mediaRecorder.start();

                    } catch (final Exception ex) {
                        // Log.i("---","Exception in thread");
                    }
                }
            });

            recording = true;
        }
    }
};

private void releaseMediaRecorder() {
    if (mediaRecorder != null) {
        mediaRecorder.reset(); // clear recorder configuration
        mediaRecorder.release(); // release the recorder object
        mediaRecorder = null;
        mCamera.lock(); // lock camera for later use
    }
}

private boolean prepareMediaRecorder() {

    List < Camera.Size > videosizes = mCamera.getParameters().getSupportedVideoSizes();
    Camera.Size videosize = videosizes.get(1);
    //Camera.Size optimalPreviewSize = getOptimalPreviewSize(previewsizes, desiredwidth, desiredheight);
    Camera.Size optimalVideoSize = getOptimalPreviewSize(videosize, desiredwidth, desiredheight);
    vWidth = optimalVideoSize.width; //mCamera.getParameters().getPreviewSize().width;
    vHeight = optimalVideoSize.height; //mCamera.getParameters().getPreviewSize().height;

    mediaRecorder = new MediaRecorder();
    mCamera.unlock();
    mediaRecorder.setCamera(mCamera);

    //startFaceDetection();
    //mPreview.setPreviewSize(optimalPreviewSize.width, optimalPreviewSize.height);
    //mCamera.unlock();
    //mMediaRecorder = new MediaRecorder();
    //mMediaRecorder.setCamera(mCamera);
    //mMediaRecorder.setVideoSize(optimalVideoSize.width, optimalVideoSize.height);
    //myCamera.setParameters(p);
    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
    mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
    mediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_LOW));
    mediaRecorder.setVideoEncodingBitRate(512 * 1000);
    mediaRecorder.setVideoFrameRate(15);
    mediaRecorder.setVideoSize(optimalVideoSize.width, optimalVideoSize.height);
    mediaRecorder.setOutputFile("/sdcard/myvideo.mp4");
    mediaRecorder.setMaxDuration(600000); // Set max duration 60 sec.
    mediaRecorder.setMaxFileSize(50000000); // Set max file size 50M

    try {
        mediaRecorder.prepare();
    } catch (IllegalStateException e) {
        releaseMediaRecorder();
        return false;
    } catch (IOException e) {
        releaseMediaRecorder();
        return false;
    }
    return true;

}

private void releaseCamera() {
    // stop and release camera
    if (mCamera != null) {
        mCamera.release();
        mCamera = null;
    }
}

private Camera.Size getOptimalPreviewSize(Camera.Size sizes, int w, int h) {
    final double ASPECT_TOLERANCE = 0.2;
    double targetRatio = (double) w / h;
    if (sizes == null) return null;

    Camera.Size optimalSize = null;
    double minDiff = Double.MAX_VALUE;

    int targetHeight = h;

    // Try to find an size match aspect ratio and size
    Camera.Size size = sizes;

    Log.d("Camera", "Checking size " + size.width + "w " + size.height + "h");
    double ratio = (double) size.width / size.height;
    if (Math.abs(ratio - targetRatio) <= ASPECT_TOLERANCE) if (Math.abs(size.height - targetHeight) < minDiff) {
        optimalSize = size;
        minDiff = Math.abs(size.height - targetHeight);
    }

    // Cannot find the one match the aspect ratio, ignore the
    // requirement
    if (optimalSize == null) {
        minDiff = Double.MAX_VALUE;
        if (Math.abs(size.height - targetHeight) < minDiff) {
            optimalSize = size;
            minDiff = Math.abs(size.height - targetHeight);
        }

    }
    return optimalSize;
}


public void startFaceDetection() {
    // Try starting Face Detection
    Camera.Parameters params = mCamera.getParameters();

    // start face detection only *after* preview has started
    if (params.getMaxNumDetectedFaces() > 0) {
        // camera supports face detection, so can start it:
        mCamera.startFaceDetection();
    }
}

下面是人脸检测监听器类:

public class FaceDetectionListener implements Camera.FaceDetectionListener {

@Override
public void onFaceDetection(Camera.Face[] faces, Camera c)
{
    if (faces.length > 0){
    Log.d("FaceDetection", "face detected: " + faces.length +
            " Face 1 Location X: " + faces[0].rect.centerX() +
            "Y: " + faces[0].rect.centerY());

    }
}

Answer 1

我使用 Mobile Vision API 从实时视频中进行人脸检测，您可以搜索 Mobile Vision API 进行人脸检测，它会工作得很好， 但我没有任何方法可以捕获检测到的人脸并将检测到的人脸从实时视频中保存在图库中