Android OpenCV - 在輪廓上繪製矩形

Question

如何將List<MatOfPoint> contours轉換爲Rect[] contoursArray，以便我可以使用Core.rectangle(mRgba, contoursArray[i].tl(), contoursArray[i].br(), (255,0,0,255), 3)在其上繪製矩形？

public Mat onCameraFrame(CvCameraViewFrame inputFrame) { 
    mRgba = inputFrame.rgba(); 
    mGray = inputFrame.gray(); 
    //Touch screen to track by color and draw rectangle on it 
    if (mItem_select && Color_Select){ 
     mDetector.process(mRgba); 
     List <MatOfPoint> contours = mDetector.getContours(); 
     Log.e(TAG, "Contours count: " + contours.size()); 
     Imgproc.drawContours(mRgba, contours, - 1, Rectangle_Color); 
     //Draw rectangle on it 
     Rect[] contoursArray = contours.toArray(); //error:Type mismatch: cannot convert from Object[] to Rect[] 
     Core.rectangle(mRgba, contoursArray.tl(), contoursArray.br(), (255, 0, 0, 255), 3); //error:Cannot invoke tl() on the array type Rect[]、Cannot invoke br() on the array type Rect[] 

     Mat colorLabel = mRgba.submat(4, 68, 4, 68); 
     colorLabel.setTo(mBlobColorRgba); 
     Mat spectrumLabel = mRgba.submat(4, 4 + mSpectrum.rows(), 70, 70 + mSpectrum.cols()); 
     mSpectrum.copyTo(spectrumLabel); 
    } 
    return mRgba; 
} 

Answer 1

嘗試使用此方法繪製矩形上countours

MatOfPoint2f approxCurve =新MatOfPoint2f（）;

 //For each contour found 
     for (int i=0; i<contours.size(); i++) 
     { 
      //Convert contours(i) from MatOfPoint to MatOfPoint2f 
      MatOfPoint2f contour2f = new MatOfPoint2f(contours.get(i).toArray()); 
      //Processing on mMOP2f1 which is in type MatOfPoint2f 
      double approxDistance = Imgproc.arcLength(contour2f, true)*0.02; 
      Imgproc.approxPolyDP(contour2f, approxCurve, approxDistance, true); 

      //Convert back to MatOfPoint 
      MatOfPoint points = new MatOfPoint(approxCurve.toArray()); 

      // Get bounding rect of contour 
      Rect rect = Imgproc.boundingRect(points); 

      // draw enclosing rectangle (all same color, but you could use variable i to make them unique) 
      Point(rect.x+rect.width,rect.y+rect.height) , new Scalar(255, 0, 0, 255), 3); 
     } 

Answer 2

非常類似的問題和工作答案在這裏提供：http://answers.opencv.org/question/25755/drawing-bounding-box-in-java/