我为我的项目制作了一个 android 应用程序。我的应用程序的目的是检测眨眼。
我使用移动视觉 api。我正在使用一个关于移动视觉的面部检测和眨眼检测代码的示例代码。
我的第一个问题是移动视觉 api 可以在后台服务上工作吗？
我的第二个问题是将相机 api 与移动视觉 api 结合起来是什么？相机 api 可以在后台服务上工作，但不能与移动视觉人脸检测类一起使用。
请帮我..
我的应用程序的服务代码是
public class ServiceClass extends Service{
private static final String TAG = "FaceTracker";
public CameraSource mCameraSource = null;
public CameraSourcePreview mPreview;
private GraphicOverlay mGraphicOverlay;
private static final int RC_HANDLE_GMS = 9001;
// permission request codes need to be < 256
private static final int RC_HANDLE_CAMERA_PERM = 2;
static int x=0;
//Camera variables
//a surface holder
private SurfaceHolder sHolder;
//a variable to control the camera
private Camera mCamera;
//the camera parameters
private Camera.Parameters parameters;
/** Called when the activity is first created. */
@Override
public void onCreate()
{
super.onCreate();
Log.d("SERVICE", "onCreate" );
// Check for the camera permission before accessing the camera. If the
// permission is not granted yet, request permission.
int rc = ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
if (rc == PackageManager.PERMISSION_GRANTED) {
createCameraSource();
} else {
//requestCameraPermission();
Toast.makeText(getApplicationContext(), "Need a permission", Toast.LENGTH_LONG).show();
}
}
/**
* Creates and starts the camera. Note that this uses a higher resolution in comparison
* to other detection examples to enable the barcode detector to detect small barcodes
* at long distances.
*/
public void createCameraSource() {
Log.d("SERVICE", "createCameraSource" );
Context context = getApplicationContext();
FaceDetector detector = new FaceDetector.Builder(context)
.setProminentFaceOnly(true) //Detection for front camera
.setClassificationType(FaceDetector.ALL_CLASSIFICATIONS)
.build();
detector.setProcessor(
new LargestFaceFocusingProcessor(detector, new BlinkTracker()));
//new MultiProcessor.Builder<>(new GraphicFaceTrackerFactory())
//.build());
if (!detector.isOperational()) {
// Note: The first time that an app using face API is installed on a device, GMS will
// download a native library to the device in order to do detection. Usually this
// completes before the app is run for the first time. But if that download has not yet
// completed, then the above call will not detect any faces.
//
// isOperational() can be used to check if the required native library is currently
// available. The detector will automatically become operational once the library
// download completes on device.
Log.w(TAG, "Face detector dependencies are not yet available.");
}
mCameraSource = new CameraSource.Builder(context, detector)
.setRequestedPreviewSize(640, 480)
.setFacing(CameraSource.CAMERA_FACING_FRONT)//using front camera
.setRequestedFps(30.0f)
.build();
Log.i("createCameraSource",mCameraSource.toString());
}
/**
* starts the camera.
*/
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this, "service starting", Toast.LENGTH_SHORT).show();
startCameraSource();
// If we get killed, after returning from here, restart
return START_STICKY;
}
/*
@Override
public void onStart(Intent intent, int startId) {
// TODO Auto-generated method stub
super.onStart(intent, startId);
Log.d("SERVICE", "onStart" );
startCameraSource();
//startCameraSource();
// mCamera = Camera.open(1);
}*/
//==============================================================================================
// Camera Source Preview
//==============================================================================================
/**
* Starts or restarts the camera source, if it exists. If the camera source doesn't exist yet
* (e.g., because onResume was called before the camera source was created), this will be called
* again when the camera source is created.
*/
public void startCameraSource() {
Log.d("SERVICE", "startCameraSource" );
// check that the device has play services available.
int code = GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(
getApplicationContext());
/*if (code != ConnectionResult.SUCCESS) {
Dialog dlg =
GoogleApiAvailability.getInstance().getErrorDialog(this, code, RC_HANDLE_GMS);
dlg.show();
}*/
if (mCameraSource != null) {
try {
Log.d("startCameraSource", "log!" );
Log.i("startCameraSource1",mCameraSource.toString());
mPreview.start(mCameraSource);
} catch (IOException e) {
Log.e(TAG, "Unable to start camera source.", e);
mCameraSource.release();
mCameraSource = null;
}
}
}
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
//==============================================================================================
// Eye Blink Tracker
//==============================================================================================
public class BlinkTracker extends Tracker<Face> {
private final double OPEN_THRESHOLD = 0.85;
private final double CLOSE_THRESHOLD = 0.50;
private int state = 0;
public void onUpdate(Detector.Detections<Face> detections, Face face) {
Log.i("BlinkTracker", "eye tracker start");
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
Log.i("BlinkTracker", "eye open");
state = 1;
}
break;
case 1:
if ((left < CLOSE_THRESHOLD) && (right < CLOSE_THRESHOLD)) {
// Both eyes become closed
Log.i("BlinkTracker", "blink occurred!");
state = 0;
}
break;
/*case 2:
if ((left > OPEN_THRESHOLD) && (right > OPEN_THRESHOLD)) {
// Both eyes are open again
Log.i("BlinkTracker", "blink occurred!");
state = 0;
}
break;*/
}
}
}
}
日志猫
07-13 09:55:04.716 17707-17707/com.hyechon.etrackermv E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.hyechon.etrackermv, PID: 17707
java.lang.RuntimeException: Unable to start service com.hyechon.etrackermv.ServiceClass@7566889 with Intent { cmp=com.hyechon.etrackermv/.ServiceClass }: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.hyechon.etrackermv.camera.CameraSourcePreview.start(com.google.android.gms.vision.CameraSource)' on a null object reference
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4079)
at android.app.ActivityThread.access$2400(ActivityThread.java:221)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1897)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7225)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void com.hyechon.etrackermv.camera.CameraSourcePreview.start(com.google.android.gms.vision.CameraSource)' on a null object reference
at com.hyechon.etrackermv.ServiceClass.startCameraSource(ServiceClass.java:255)
at com.hyechon.etrackermv.ServiceClass.onStartCommand(ServiceClass.java:136)
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4062)
at android.app.ActivityThread.access$2400(ActivityThread.java:221)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1897)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7225)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
07-13 09:55:05.666 17707-17777/com.hyechon.etrackermv I/Vision：连接错误：空 07-13 10:00:04.761 17707-17707/com.hyechon.etrackermv I/过程：发送信号。PID：17707 SIG：9