Afnman's profile - activity

By setting a threshold. ex. model->set("threshold", 100.0) Anything above 100.0 will be considered as alien

Sorry, I can't accept my own answer due to......50 points thing.

That's my problem too. Maybe in your case you can find it with trials and errors. Others set the threshold as the maximum value of minimum Euclidean distances of each face from other faces In general case, the threshold varies according to illuminations,faces background,translations etc. It If you find something that works for all situations, I would like to know it.

You must set a threshold for your Face Recognition Algorithm.For Example:

Ptr<FaceRecognizer> model = createEigenFaceRecognizer()
    model->set("threshold", 3000.0);

if the distance of your tested face from the trained face is above 3000.0 (threshold) then will be considered as unknown (-1).

See details here: http://docs.opencv.org/modules/contrib/doc/facerec/facerec_api.html

I have found a solution to my problem by doing this trick:

 Ptr<FaceRecognizer> model =createLBPHFaceRecognizer();
 model.addref();
 jlong ptr =(jlong)model.obj;

where ptr is the nativeObject's address.

Thank you very much for your answers. Actually, after this(in JNI function):

 FaceRecognizer* model = createLBPHFaceRecognizer();
int k=model->getInt("radius");  //error here

I get segfault but if I use Ptr<facerecognizer> model=createLBPHFaceRecognizer() then I don't. I still have issues with the pointer returned by createLBPHFaceRecognizer.

I have done this:

-First I call

 JNIEXPORT jlong JNICALL Java_org_opencv_samples_fd_LBPFaceRecognizer_nativeCreateObject (JNIEnv * jenv, jclass) { FaceRecognizer* model = createLBPHFaceRecognizer();
return (jlong)model; }

that returns jlong memory address and stored it in my wrapper object.

Then I call

JNIEXPORT int JNICALL Java_org_opencv_samples_fd_LBPFaceRecognizer_nativeGetNeighbor
(JNIEnv * jenv, jclass, jlong ptr) {
int neigh=((FaceRecognizer*)ptr)->getInt("radius"),
return neigh;
}

with ptr equal to model's address returned by the previous function (nativeCreateObject) I still get segfault.

Hello, I am trying to use FaceRecognizer class (from contrib folder).

I have created LBPFaceRecognizer class that inherits from FaceRecognizer class with one method nativecreateObject.

the corresponding JNI nativecreateOBject function:

   JNIEXPORT jlong JNICALL Java_org_opencv_samples_fd_LBPFaceRecognizer_nativeCreateObject
(JNIEnv * jenv, jclass)
{
     Ptr<FaceRecognizer> model;
              model= createLBPHFaceRecognizer();   
return  (jlong)model.obj; //Problem here!?!?!?!? What should I return?
}

Then I call the nativeCreateObject in the constructor of LBPFaceRecognizer:

public LBPFaceRecognizer() {
        super(nativeCreateObject());}

The problem is here: (inside the OnManagerConnected()):

BPFaceRecognizer model= new LBPFaceRecognizer();    
                 int r=model.getInt("radius"); //!?!?! CRASH HERE

I get Fatal signal 11 (SIGSEGV) at 0x00000028. when the native method getInt0(nativeObject,"radious") is called.

how can I use the FaceRecognizer ??