如何在 Android OpenCV 中捕获图像

Question

我正在从事一个图像处理项目，现在我遇到了一个问题，我导入了 OpenCV 库，我将 RGB 帧转换为二进制帧。现在我不知道如何捕获二进制图像并将其存储在数据库中。没有关于 OpenCV 库的教程。所以任何人都可以帮我解决这个问题。我的编码如下..

public class MainActivity extends AppCompatActivity implements View.OnTouchListener,CameraBridgeViewBase.CvCameraViewListener2 {

private static final String TAG = MainActivity.class.getCanonicalName();
private CameraBridgeViewBase mOpenCvCameraView;
private Mat mRgba;
private Scalar mBlobColorHsv;
private Scalar mBlobColorRgba;

private Mat mIntermediateMat;
private Mat mGray;
Mat hierarchy;


List<MatOfPoint> contours;


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();
                mOpenCvCameraView.setOnTouchListener(MainActivity.this);
            }
            break;
            default: {
                super.onManagerConnected(status);
            }
            break;

        }
    }

};
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);


    mOpenCvCameraView=(CameraBridgeViewBase)findViewById(R.id.opencv_tutorial_activity_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();
        if(!OpenCVLoader.initDebug()) {
            OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mLoaderCallback);
        }
        else{
            mLoaderCallback.onManagerConnected(LoaderCallbackInterface.SUCCESS);
        }
    }
}
@Override
public void onDestroy(){
    super.onPause();
    if(mOpenCvCameraView!=null)
        mOpenCvCameraView.disableView();
}

@Override
public boolean onTouch(View v, MotionEvent event) {

    return false;
}


@Override
public void onCameraViewStarted(int width, int height) {
    mRgba=new Mat();
    mBlobColorRgba=new Scalar(255);
    mBlobColorHsv=new Scalar(255);
    mRgba = new Mat(height, width, CvType.CV_8UC4);
    mIntermediateMat = new Mat(height, width, CvType.CV_8UC4);
    mGray = new Mat(height, width, CvType.CV_8UC1);
    hierarchy = new Mat();
}

简而言之，我想要做的是创建一个按钮，并在 onclick 方法中我想捕获图像并且必须显示图像的预览。请有人帮我解决这个问题。提前致谢。

Answer 1

如果要预览图像，则必须将 mat 转换为位图，然后将其显示在 ImageView 中。您可以设置一个 CvCameraViewListener 来接收位图。像这样

    private Mat mat;
    private boolean showPreviews;
        private BaseLoaderCallback mLoaderCallback=new BaseLoaderCallback(this) {
            @Override
            public void onManagerConnected(int status) {
                switch (status) {
                    case LoaderCallbackInterface.SUCCESS: {
                        Log.i(TAG, "OpenCV loaded successfully");
                      someButton.setOnclickListener(new View.OnclickListener(View v){
                               showPreviews = !showPreviews;
});
                        mOpenCvCameraView.enableView();
                        mOpenCvCameraView.setOnTouchListener(MainActivity.this);
        mOpenCvCameraView.setCvCameraViewListener(MainActivity.this);

                    }
                    break;
                    default: {
                        super.onManagerConnected(status);
                    }
                    break;

                }
            }

        };

        @Override
            public void onCameraViewStarted(int width, int height) {
                // TODO Auto-generated method stub

            }
            @Override
            public void onCameraViewStopped() {
                // TODO Auto-generated method stub

            }
            @Override
            public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
                // TODO Auto-generated method stub
               if(!showPreviews)
      mat = inputFrame.rgba();
           // you can return a modified mat if you want to display it in opencv
                return mat;
            }