不满意的链接错误 - 适用于Android的OpenCV非本机

Question

几天前,我询问了一个UnsatisfiedLinkError来自非原生OpenCV代码的问题.我认为在重新安装Eclipse并关闭/重新打开所有软件包之后问题就解决了,但是在我将OpenCV代码放入现有onCreate()方法之后它又回来了.

我创建了一个名为Start的活动的新Android应用程序.然后我去了项目属性并将OpenCV添加为库.这是activity(Start.java)的代码:

package com.test;

import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.view.Menu;

public class Start extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_start);

        Mat Image = Highgui.imread("/image.jpg");
        if (Image == null) {
            AlertDialog ad = new AlertDialog.Builder(this).create(); 
            ad.setMessage("Fatal error: can't open /image.jpg!");  
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_start, menu);
        return true;
    }
}

这是日志:

08-13 12:26:14.791: E/Trace(1067): error opening trace file: No such file or directory (2)
08-13 12:26:15.191: W/dalvikvm(1067): No implementation found for native Lorg/opencv/highgui/Highgui;.imread_1:(Ljava/lang/String;)J
08-13 12:26:15.191: D/AndroidRuntime(1067): Shutting down VM
08-13 12:26:15.191: W/dalvikvm(1067): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
08-13 12:26:15.201: E/AndroidRuntime(1067): FATAL EXCEPTION: main
08-13 12:26:15.201: E/AndroidRuntime(1067): java.lang.UnsatisfiedLinkError: Native method not found: org.opencv.highgui.Highgui.imread_1:(Ljava/lang/String;)J
08-13 12:26:15.201: E/AndroidRuntime(1067):     at org.opencv.highgui.Highgui.imread_1(Native Method)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at org.opencv.highgui.Highgui.imread(Highgui.java:324)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at com.test.Start.onCreate(Start.java:18)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.Activity.performCreate(Activity.java:5008)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.os.Looper.loop(Looper.java:137)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at android.app.ActivityThread.main(ActivityThread.java:4745)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at java.lang.reflect.Method.invokeNative(Native Method)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at java.lang.reflect.Method.invoke(Method.java:511)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
08-13 12:26:15.201: E/AndroidRuntime(1067):     at dalvik.system.NativeStart.main(Native Method)

同样,这是非本机代码,因此具有不满意的链接错误没有多大意义.

Answer 1

经过一番搜索,我发现了这个:

"3.如果您的应用程序项目没有JNI部分,只需将相应的OpenCV本机库从/ sdk/native/libs /复制到项目目录到文件夹libs /."

这意味着复制\ armeabi,\ armeabi-v7a和\ x86文件夹.

"4.在您的应用程序中启用OpenCV的最后一步是在调用OpenCV API之前的Java初始化代码.例如,可以在Activity类的静态部分中完成,该部分仅在任何实例之前执行一次.创建了类:

static {
    if (!OpenCVLoader.initDebug()) {
        // Handle initialization error
    }
}

或者,您可以将其放在onCreate方法中:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_load_image);
    if (!OpenCVLoader.initDebug()) {
        // Handle initialization error
    }
    [...]
}

现在它有效!

Answer 2

你应该使用

if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
{
    Log.e("TEST", "Cannot connect to OpenCV Manager");
}

在OnCreate()并使用

private BaseLoaderCallback  mOpenCVCallBack = new BaseLoaderCallback(this) {
    @Override
    public void onManagerConnected(int status) {
        switch (status) {
                case LoaderCallbackInterface.SUCCESS:
                {
                               Mat Image = Highgui.imread("/image.jpg");
                               if (Image == null) {
                                   AlertDialog ad = new AlertDialog.Builder(this).create(); 
                                   ad.setMessage("Fatal error: can't open /image.jpg!");  
                                }
                } break;
                default:
                {
                    super.onManagerConnected(status);
                } break;
            }
    }
    };

Answer 3

在大多数情况下,在调用openCV之前这样的行就足够了:"System.loadLibrary(Core.NATIVE_LIBRARY_NAME);"