Android NDK OpenCV - No implementation found for native

Issue

can you help me handle my errors? I have read a lot of tips how to fix them but nothing helped me. I also know that there are similar question already asked but they didnt help me. So I give a chance to ask you:

I am trying to make Android application what takes Image from gallery and call native function written in c++ to make it grey.

In my main activity is:

static {
        if(!OpenCVLoader.initDebug())
        {
            Log.e("tom", "Tomasku opencv problem static");
        }
        else
        {
            Log.e("tom", "OPENCV NACITANE");
            System.loadLibrary("halgorithm");
        }
    }

***In the same Activity I call another activity(EditorActivity):

Intent i = new Intent(this, EditorActivity.class);
                ...
                i.putExtra("path", selectedImagePath); //path to image from gallery
                startActivity(i);

***In my EditorActivity:

...
public native int fce(long matAddrRgba, long matAddrGray);
...

fce(image.getNativeObjAddr(), image_gray.getNativeObjAddr());
// and here it crashes

**In my halgorithm.cpp

#include <jni.h>
#include <string.h>
#include <stdio.h>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/features2d/features2d.hpp>
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc_c.h"

//using namespace std;
using namespace cv;

extern "C"
{

JNIEXPORT jint JNICALL Java_com_example_hematoma_MainActivity_fce(JNIEnv*, jobject, jlong addrRgba, jlong addrGray) {

    Mat& mRgb = *(Mat*)addrRgba;
    Mat& mGray = *(Mat*)addrGray;

    int conv;
    jint retVal;

    conv = toGray(mRgb, mGray);
    retVal = (jint)conv;

    return retVal;

}

}

int toGray(Mat img, Mat& gray)
{
    cvtColor(img, gray, CV_RGBA2GRAY); // Assuming RGBA input

    if (gray.rows == img.rows && gray.cols == img.cols)
    {
        return 1;
    }
    return 0;
}

**In my Android.mk

include $(CLEAR_VARS)

OPENCV_INSTALL_MODULES:=on
OPENCV_CAMERA_MODULES:=on
include /home/nemesis/adt-bundle-linux-x86_64-20140702/OpenCV-2.4.10-android-sdk/sdk/native/jni/OpenCV.mk

LOCAL_MODULE := halgorithm
LOCAL_SRC_FILE := halgorithm.cpp

LOCAL_C_INCLUDES := /home/nemesis/adt-bundle-linux-x86_64-20140702/OpenCV-2.4.10-android-sdk/sdk/native/jni/include

include $(BUILD_SHARED_LIBRARY)

***LogCat

04-30 13:16:28.320: W/dalvikvm(3863): No implementation found for native Lcom/example/hematoma/EditorActivity;.fce (JJ)I
04-30 13:16:28.320: D/AndroidRuntime(3863): Shutting down VM
04-30 13:16:28.320: W/dalvikvm(3863): threadid=1: thread exiting with uncaught exception (group=0x40185760)
04-30 13:16:28.320: E/AndroidRuntime(3863): FATAL EXCEPTION: main
04-30 13:16:28.320: E/AndroidRuntime(3863): java.lang.UnsatisfiedLinkError: fce
04-30 13:16:28.320: E/AndroidRuntime(3863):     at com.example.hematoma.EditorActivity.fce(Native Method)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at com.example.hematoma.EditorActivity$3.onClick(EditorActivity.java:166)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at android.view.View.performClick(View.java:3110)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at android.view.View$PerformClick.run(View.java:11934)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at android.os.Handler.handleCallback(Handler.java:587)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at android.os.Handler.dispatchMessage(Handler.java:92)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at android.os.Looper.loop(Looper.java:132)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at android.app.ActivityThread.main(ActivityThread.java:4123)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at java.lang.reflect.Method.invokeNative(Native Method)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at java.lang.reflect.Method.invoke(Method.java:491)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)
04-30 13:16:28.320: E/AndroidRuntime(3863):     at dalvik.system.NativeStart.main(Native Method)

Thanks in advance!

****************************EDITED***********************

After your suggestions I changed:

***In Android.mk:

JNIEXPORT jint JNICALL 
Java_com_example_hematoma_**EditorActivity**_fce(JNIEnv*, jobject, jlong addrRgba, jlong addrGray) {...}

***In EditorActivity: I am calling System.loadLibrary("halgorithm") before native methode.

static {
        if(!OpenCVLoader.initDebug())
        {
            Log.e("tom", "Tomasku opencv problem static");
        }
        else
        {
            Log.e("tom", "OPENCV NACITANE");
            System.loadLibrary("halgorithm");
        }
    }

But it didnt fixed my error. There is the same error :/

***LogCat

04-30 13:36:21.760: W/dalvikvm(4255): No implementation found for native Lcom/example/hematoma/EditorActivity;.fce (JJ)I
04-30 13:36:21.760: D/AndroidRuntime(4255): Shutting down VM
04-30 13:36:21.760: W/dalvikvm(4255): threadid=1: thread exiting with uncaught exception (group=0x40185760)
04-30 13:36:21.760: E/AndroidRuntime(4255): FATAL EXCEPTION: main
04-30 13:36:21.760: E/AndroidRuntime(4255): java.lang.UnsatisfiedLinkError: fce
04-30 13:36:21.760: E/AndroidRuntime(4255):     at com.example.hematoma.EditorActivity.fce(Native Method)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at com.example.hematoma.EditorActivity$3.onClick(EditorActivity.java:166)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at android.view.View.performClick(View.java:3110)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at android.view.View$PerformClick.run(View.java:11934)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at android.os.Handler.handleCallback(Handler.java:587)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at android.os.Handler.dispatchMessage(Handler.java:92)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at android.os.Looper.loop(Looper.java:132)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at android.app.ActivityThread.main(ActivityThread.java:4123)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at java.lang.reflect.Method.invokeNative(Native Method)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at java.lang.reflect.Method.invoke(Method.java:491)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)
04-30 13:36:21.760: E/AndroidRuntime(4255):     at dalvik.system.NativeStart.main(Native Method)

Solution

After few days of hopelessness :D I solve my problem. The issue was that $(OPENCV_INSTALL_MODULES) should be equal. At the line OPENCV_INSTALL_MODULES:=on in my Android.mk file.

I overrided OPENCV_INSTALL_MODULES:=on

to

OPENCV_INSTALL_MODULES=on

and now it works.... Perhaps it might help to someone else too :)

Answered By - User