Question

我是opencv的新手。我想在android中使用opencv在实时视频上应用sobel滤镜，但我没有这样做。当我在opencv中使用sobel的内置功能时，它会给我一个白色的空白屏幕。我搜索了很多，但没有找到我的错误..

package com.example.bismanawaz.opencvpractice;

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 org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;


public class MainActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2{

    private CameraBridgeViewBase mOpenCvCameraView;
    private Mat sobell;
    public static final int CV_8UC1=0;
    private static final String TAG ="OpenCV" ;

    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;
            }
        }
    };

    @Override
    public void onResume()
    {
        super.onResume();
        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_7, this, mLoaderCallback);
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Log.i(TAG, "called onCreate");
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        setContentView(R.layout.activity_main);
        mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.HelloOpenCvView);
        mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
        mOpenCvCameraView.setCvCameraViewListener(this);
    }

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

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

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * This method is invoked when camera preview has started. After this method is invoked
     * the frames will start to be delivered to client via the onCameraFrame() callback.
     *
     * @param width  -  the width of the frames that will be delivered
     * @param height - the height of the frames that will be delivered
     */
    @Override
    public void onCameraViewStarted(int width, int height) {
        sobell = new Mat();
    }

    /**
     * This method is invoked when camera preview has been stopped for some reason.
     * No frames will be delivered via onCameraFrame() callback after this method is called.
     */
    @Override
    public void onCameraViewStopped() {

    }

    /**
     * This method is invoked when delivery of the frame needs to be done.
     * The returned values - is a modified frame which needs to be displayed on the screen.
     *
     * @param inputFrame
     */
    @Override
    public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
        Imgproc.Sobel(inputFrame.gray(),sobell,CV_8UC1,1,1,3);
        return sobell;
    }
}

Answer 1

这是我做索贝尔的方法。

    public static Mat FindSobelEdges(Mat mat) {
    Imgproc.Sobel(mat, mat, CvType.CV_8UC1, 1, 1);
    return mat;
    }

我认为你的问题是错误的参数。请检查Imgproc.Sobel doc：

Imgproc.Sobel

opencv实时视频帧没有在android中显示sobel输出

1 个答案: