如何使用Android Opencv檢測目標上的彈孔

Question

我正在一個項目中工作，在該項目中，我必須掃描目標並識別目標中的洞，並且必須根據拍攝得分。我不知道如何識別目標中的洞的確切代碼。我導入了opencv庫，並通過一個程序，如果我觸摸它將識別相應的顏色。現在我被困在編碼部分。這是給我的目標工作表的屏幕截圖。

任何人都可以請幫我如何進一步進行。提前致謝。

Answer 1

做你想你應該：

1) find white areas with max brightness; 
2) find bounding contours of areas with max brightness (from p.1); 
3) find bounding boxes for contours from p.2; 
4) count bounding boxes. 

，也考慮到一些特殊情況下，如在你的形象「孿生」孔。

要在Android上實現這個步驟，最簡單的方法是使用OpenCV。如何將它添加到你的項目描述中here（你應該做一些工作來做它：從here下載SDK並正確添加它）。那麼你應該看看在Android中使用OpenCV的一些教程，例如，official。而不是，您可以使用這樣的代碼（圖像添加到演示項目爲target.png的drawable文件夾）：

public class MainActivity extends AppCompatActivity { 

    public static final String TAG = MainActivity.class.getSimpleName(); 

    private ImageView mImageView; 
    private Button mProcessButton; 

    private Mat mSourceImageMat; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     mImageView = (ImageView) findViewById(R.id.target_image_view); 
     mProcessButton = (Button) findViewById(R.id.process_button); 
     mProcessButton.setVisibility(View.INVISIBLE); 

     mProcessButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       processImage(); 
      } 
     }); 
    } 

    private void processImage() { 
     try { 
      mSourceImageMat = Utils.loadResource(this, R.drawable.target); 
      Bitmap bm = Bitmap.createBitmap(mSourceImageMat.cols(), mSourceImageMat.rows(),Bitmap.Config.ARGB_8888); 

      final Mat mat = new Mat(); 
      final List<Mat> channels = new ArrayList<>(3); 

      mSourceImageMat.copyTo(mat); 

      // split image channels: 0-H, 1-S, 2-V 
      Imgproc.cvtColor(mat, mat, Imgproc.COLOR_RGB2HSV); 
      Core.split(mat, channels); 
      final Mat frameV = channels.get(2); 

      // find white areas with max brightness 
      Imgproc.threshold(frameV, frameV, 245, 255, Imgproc.THRESH_BINARY); 

      // find contours 
      List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); 
      Imgproc.findContours(frameV, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); 

      // find average contour area for "twin" hole detection 
      double averageArea = 0; 
      int contoursCount = 0; 
      Iterator<MatOfPoint> each = contours.iterator(); 
      while (each.hasNext()) { 
       averageArea += Imgproc.contourArea(each.next()); 
       contoursCount++; 
      } 
      if (contoursCount != 0) { 
       averageArea /= contoursCount; 
      } 

      int holesCount = 0; 
      each = contours.iterator(); 
      while (each.hasNext()) { 
       MatOfPoint contour = each.next(); 

       MatOfPoint2f areaPoints = new MatOfPoint2f(contour.toArray()); 
       RotatedRect boundingRect = Imgproc.minAreaRect(areaPoints); 
       Point rect_points[] = new Point[4]; 

       boundingRect.points(rect_points); 
       for(int i=0; i<4; ++i){ 
        Imgproc.line(mSourceImageMat, rect_points[i], rect_points[(i+1)%4], new Scalar(255,0,0), 2); 
       } 
       holesCount++; 

       Imgproc.putText(mSourceImageMat, Integer.toString(holesCount), new Point(boundingRect.center.x + 20, boundingRect.center.y), 
         Core.FONT_HERSHEY_PLAIN, 1.5 ,new Scalar(255, 0, 0)); 

       // case of "twin" hole (like 9 & 10) on image 
       if (Imgproc.contourArea(contour) > 1.3f * averageArea) { 
        holesCount++; 
        Imgproc.putText(mSourceImageMat, ", " + Integer.toString(holesCount), new Point(boundingRect.center.x + 40, boundingRect.center.y), 
          Core.FONT_HERSHEY_PLAIN, 1.5 ,new Scalar(255, 0, 0)); 
       } 

      } 

      // convert to bitmap: 
      Utils.matToBitmap(mSourceImageMat, bm); 
      mImageView.setImageBitmap(bm); 

      // release 
      frameV.release(); 
      mat.release(); 

     } catch (IOException e) { 
      e.printStackTrace(); 
     } 


    } 

    @Override 
    protected void onPostResume() { 
     super.onPostResume(); 
     OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_1_0, this, mOpenCVLoaderCallback); 
    } 

    private BaseLoaderCallback mOpenCVLoaderCallback = new BaseLoaderCallback(this) { 
     @Override 
     public void onManagerConnected(int status) { 
      switch (status) { 
       case LoaderCallbackInterface.SUCCESS: { 
        Log.i(TAG, "OpenCV loaded successfully"); 
        mProcessButton.setVisibility(View.VISIBLE); 
       } break; 
       default: { 
        super.onManagerConnected(status); 
       } break; 
      } 
     } 
    }; 
} 

如果按FIND HOLESButton你得到結果這樣

對於其他圖片您應該調整245, 255中的值

Imgproc.threshold(frameV, frameV, 245, 255, Imgproc.THRESH_BINARY); 

一行。

更新：MainActivity佈局（activity_main.xml）：

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:id="@+id/activity_main" 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:paddingBottom="@dimen/activity_vertical_margin" 
    android:paddingLeft="@dimen/activity_horizontal_margin" 
    android:paddingRight="@dimen/activity_horizontal_margin" 
    android:paddingTop="@dimen/activity_vertical_margin" 
    tools:context=".MainActivity"> 

    <ImageView 
     android:id="@+id/target_image_view" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:scaleType="fitCenter" 
     app:srcCompat="@drawable/target" 
     android:layout_alignParentTop="true" 
     android:layout_alignParentStart="true" 
     android:layout_above="@+id/process_button"/> 

    <Button 
     android:id="@+id/process_button" 
     android:text="Find holes" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentBottom="true" 
     android:layout_alignParentStart="true" 
     android:layout_alignParentEnd="true"/> 

</RelativeLayout>