opencv android中背景减法中的应用方法错误

Posted 2023-02-22

【中文标题】opencv android中背景减法中的应用方法错误

【英文标题】：error in apply method in Background subtraction in opencv android

【发布时间】：2014-04-14 08:39:47

【问题描述】：

我想在 InputFrame 上做背景减法，并想返回前景蒙版。 我面临错误，因为下面有人可以帮我解决它 在此先感谢

我的代码：

package org.opencv.samples.tutorial1;

import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Mat;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.video.BackgroundSubtractorMOG;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SurfaceView;
import android.view.WindowManager;
import android.widget.Toast;

public class Tutorial1Activity extends Activity implements CvCameraViewListener2 
    private static final String TAG = "Divyesh::Activity";

    private CameraBridgeViewBase mOpenCvCameraView;
    private boolean              mIsJavaCamera = true;
    private MenuItem             mItemSwitchCamera = null;

    public Point p1 = new Point(10, 2);
    public Point p2 = new Point(100, 20);
    public  Scalar scalar = new Scalar(255, 255, 255);
    public Mat fgMask;
    public Mat mRgba, mGray, mRgb;
    //public BackgroundSubtractor pMog, pMog2;
    BackgroundSubtractorMOG pMog;


    private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) 

        @Override
        public void onManagerConnected(int status) 
            switch (status) 
                case LoaderCallbackInterface.SUCCESS:
                
                    Log.i(TAG, "OpenCV loaded successfully");
                    mOpenCvCameraView.enableView();
                 break;
                default:
                
                    super.onManagerConnected(status);
                 break;
            
        
    ;


    public Tutorial1Activity() 
        Log.i(TAG, "Instantiated new " + this.getClass());
    

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) 
        Log.i(TAG, "called onCreate");
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

        setContentView(R.layout.tutorial1_surface_view);

        if (mIsJavaCamera)
            mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.tutorial1_activity_java_surface_view);
        else
            mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.tutorial1_activity_native_surface_view);

        mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);

        mOpenCvCameraView.setCvCameraViewListener(this);

    

    @Override
    public void onPause()
    
        super.onPause();
        if (mOpenCvCameraView != null)
            mOpenCvCameraView.disableView();
    

    @Override
    public void onResume()
    
        super.onResume();
        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3, this, mLoaderCallback);
    

    public void onDestroy() 
        super.onDestroy();
        if (mOpenCvCameraView != null)
            mOpenCvCameraView.disableView();
    

    @Override
    public boolean onCreateOptionsMenu(Menu menu) 
        Log.i(TAG, "called onCreateOptionsMenu");
        mItemSwitchCamera = menu.add("Toggle Native/Java camera");
        return true;
    

    @Override
    public boolean onOptionsItemSelected(MenuItem item) 
        String toastMesage = new String();
        Log.i(TAG, "called onOptionsItemSelected; selected item: " + item);

        if (item == mItemSwitchCamera) 
            mOpenCvCameraView.setVisibility(SurfaceView.GONE);
            mIsJavaCamera = !mIsJavaCamera;

            if (mIsJavaCamera) 
                mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.tutorial1_activity_java_surface_view);
                toastMesage = "Java Camera";
             else 
                mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.tutorial1_activity_native_surface_view);
                toastMesage = "Native Camera";
            

            mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
            mOpenCvCameraView.setCvCameraViewListener(this);
            mOpenCvCameraView.enableView();
            Toast toast = Toast.makeText(this, toastMesage, Toast.LENGTH_LONG);
            toast.show();
        

        return true;
    

    public void onCameraViewStarted(int width, int height) 
        mRgba = new Mat();
        mGray = new Mat();
        mRgb = new Mat();
        fgMask = new Mat();
        Log.i(TAG, "Before subtractor");
        pMog = new BackgroundSubtractorMOG();
    

    public void onCameraViewStopped() 
    

    public Mat onCameraFrame(CvCameraViewFrame inputFrame) 
        Log.i(TAG, "Before input frame");
        mRgba = inputFrame.rgba();
        //Imgproc.cvtColor(mRgba, mRgb, Imgproc.COLOR_RGBA2RGB);
        Log.i(TAG,"Before apply");
        pMog.apply(mRgba, fgMask);
        Log.i(TAG,"After apply");
        //Imgproc.cvtColor(fgMask, mRgba, Imgproc.COLOR_GRAY2RGBA);
        return fgMask;

    

我的错误在这里：

/** *

计算前景掩码。

* * @param image 下一个视频帧。 * @param fgmask 输出前景掩码为 8 位二进制图像。 * * @见org.opencv.video.BackgroundSubtractor.operator() */

public  void apply(Mat image, Mat fgmask)


    apply_1(nativeObj, image.nativeObj, fgmask.nativeObj);

    return;

如果你能解决它或者能给一些指导的话，非常感谢............

【问题讨论】：

现在你到底得到了什么错误？

我在运行时出现黑屏....但根据日志仍在接收帧

这可能令人不快，但不是真正的错误。一个模型必须在那里接受训练，你通常不会在返回的第一帧中得到正确的结果。使用历史等参数。

我会尝试和thanx兄弟

兄弟它不工作历史上可能有什么？？？？

【参考方案1】：

我之前没有使用或使用过背景减法，但请尝试在您的代码中进行以下编辑。

mRgba = inputFrame.rgba();
Imgproc.cvtColor(mRgba, mRgb, Imgproc.COLOR_RGBA2BGR,4);
Log.i(TAG,"Before apply");
pMog.apply(mRgb, fgMask);
Log.i(TAG,"After apply");
Imgproc.cvtColor(fgMask, mRgb, Imgproc.COLOR_GRAY2BGR,3);
Imgproc.cvtColor(mRgb, mRgba, Imgproc.COLOR_BGR2RGBA,4);
return fgMask;

Also check this link. I think it might help:http://www.codeproject.com/Articles/791145/Motion-Detection-in-Android-Howto

希望这会有所帮助。