Hi everyone, i want to add a new method predict to the class FaceRecognizer in order to obtain all the labels and all the distances from the prediction both with FisherFace algorithm and LBPH algorithm. So my idea is to extend the class FaceRecognizer creating two classes ExtFisherFaceRecognizer and ExtLBPHFaceRecognizer showed below (for brevity i'll show only the code regarding FisherFace):
public class ExtFisherFaceRecognizer extends BasicFaceRecognizer{
protected ExtFisherFaceRecognizer(long addr)
{
super(addr);
System.out.println("Fisher Face Recognizer created");
}
public Vector predictVector(Mat image)
{
return predictVec(nativeObj,image.nativeObj);
}
@Override
protected void finalize() throws Throwable {
System.out.println("Java deleting fisher face recognizer");
delete(nativeObj);
}
private static native Vector predictVec(long nativeObj,long src_nativeObj);
private static native void delete(long nativeObj);
}
I create the model using the class FaceExt that call the respective native methods:
public class FaceExt {
public static ExtFisherFaceRecognizer createExtFisherFaceRecognizer()
{
ExtFisherFaceRecognizer recognizer = new ExtFisherFaceRecognizer(createFisherFaceRecognizer());
return recognizer;
}
public static ExtLBPHFaceRecognizer createExtLBPHFaceRecognizer()
{
ExtLBPHFaceRecognizer recognizer = new ExtLBPHFaceRecognizer(createLBPHFaceRecognizer());
return recognizer;
}
private static native long createFisherFaceRecognizer();
private static native long createLBPHFaceRecognizer();
}
And this is the cpp file that implements the native methods; i omit the details regarding building of result vector to java side:
/*includes*/
Ptr<FaceRecognizer> fisherRecognizer;
Ptr<FaceRecognizer> lbphRecognizer;
extern "C"
{
JNIEXPORT jlong JNICALL Java_facerecognition_FaceExt_createFisherFaceRecognizer(JNIEnv *env, jclass thisObj)
{
fisherRecognizer = createFisherFaceRecognizer();
return (jlong) &fisherRecognizer;
}
JNIEXPORT jlong JNICALL Java_facerecognition_FaceExt_createLBPHFaceRecognizer(JNIEnv *env, jclass thisObj)
{
lbphRecognizer = createLBPHFaceRecognizer();
return (jlong) &lbphRecognizer;
}
JNIEXPORT jobject JNICALL Java_facerecognition_ExtFisherFaceRecognizer_predictVec(JNIEnv *env, jclass thisObj, jlong model, jlong image)
{
try
{
Ptr<FaceRecognizer> faceRec = *((Ptr<FaceRecognizer>*) model);
Mat& img = *((Mat*) image);
faceRec->predict(img,label,dist);
vector<int> labels;
vector<double> confidences;
faceRec->predictVec(img,labels,confidences);
jclass classVector = env->FindClass("java/util/Vector");
...
jobject objVectorResult = env->NewObject(classVector,cntVector);
...
return objVectorResult;
}
catch(cv::Exception e)
{ }
catch (...)
{ }
}
JNIEXPORT jobject JNICALL Java_facerecognition_ExtLBPHFaceRecognizer_predictVec(JNIEnv *env, jclass thisObj, jlong model, jlong image)
{
try
{
Ptr<FaceRecognizer> faceRec = *((Ptr<FaceRecognizer>*) model);
Mat& img = *((Mat*) image);
vector<int> labels;
vector<double> confidences;
faceRec->predictVec(img,labels,confidences);
jclass classVector = env->FindClass("java/util/Vector");
...
jobject objVectorResult = env->NewObject(classVector,cntVector);
...
return objVectorResult;
}
catch(cv::Exception e)
{ }
catch (...)
{ }
}
JNIEXPORT void JNICALL Java_facerecognition_ExtFisherFaceRecognizer_delete(JNIEnv *env, jclass thisObj, jlong model)
{
Ptr<FaceRecognizer> faceRec = *((Ptr<FaceRecognizer>*) model);
delete faceRec;
cout<<"C++ deleted fisher face recognizer"<<endl;
return;
}
JNIEXPORT void JNICALL Java_facerecognition_ExtLBPHFaceRecognizer_delete(JNIEnv *env, jclass thisObj, jlong model)
{
Ptr<FaceRecognizer> faceRec = *((Ptr<FaceRecognizer>*) model);
delete faceRec;
cout<<"C++ deleted lbph face recognizer"<<endl;
return;
}
}
As you can see from the code above the prototype of the native method predictVec is the follow:
void predictVec(InputArray _src, vector<int>& labels, vector<double>& confidences)
I modified the source of OpenCV face module adding this new method in such way that works for what i want. Until i create the models all works fine but when i try to call an inherited method from BasicFaceRecognizer that extends the class FaceRecognizer or this new method predictVec, at the end of execution i obtain the error: pure virtual method called terminate called without an active exception. I have no idea what is the problem since using the methods of .jar library to create FisherFace and LBPH models all works fine.
I hope i was clear in explaining my problem and thanks you in advance for your time and your help.