OpenCV haarCascade whit 光流跟踪

问题描述

在使用Haar Cascade检测后，我正在尝试在android中使用光流跟踪对象，如下面的代码所示，我遇到了这个错误，谁能帮我这个

E/cv::error(): OpenCV(3.4.12) 错误：断言失败 ((npoints = prevPtsMat.checkVector(2,CV_32F,true)) >= 0) in virtual void cv::{anonymous} ::SparsePyrLKOpticalFlowImpl::calc(cv::InputArray,cv::InputArray,cv::InputOutputArray,cv::OutputArray,cv::OutputArray),文件/build/3_4_pack-android/opencv/modules/视频/src/lkpyramid.cpp，第 1259 行 E/org.opencv.video: video::calcopticalFlowPyrLK_15() 捕获 cv::Exception: OpenCV(3.4.12) /build/3_4_pack-android/opencv/modules/video/src/lkpyramid.cpp:1259: 错误: ( -215:Assertion Failed) (npoints = prevPtsMat.checkVector(2,true)) >= 0 in function 'virtual void cv::{anonymous}::SparsePyrLKOpticalFlowImpl::calc(cv::InputArray,cv::OutputArray)' E/AndroidRuntime：致命异常：线程 2 进程：opencv.org，PID：31380 CvException [org.opencv.core.CvException: cv::Exception: OpenCV(3.4.12) /build/3_4_pack-android/opencv/modules/video/src/lkpyramid.cpp:1259: 错误: (-215:Assertion Failed ) (npoints = prevPtsMat.checkVector(2,cv::OutputArray)' ]

enter code hereMatOfRect cars = new MatOfRect();

    if (mDetectorType == JAVA_DETECTOR) {
        if (mJavaDetector != null) {
            mJavaDetector.detectMultiScale(matGray,cars,1.1,2,// Todo: objdetect.CV_HAAR_SCALE_IMAGE
                    new Size(mAbsoluteCarSize,mAbsoluteCarSize),new Size());

        }

    }
    else {
        Log.e(TAG,"Detection method is not selected!");
    }

    Rect[] carsArray = cars.toArray();
    ArrayList<Point> CurrentCars = new ArrayList<>();

    for (int i = 0; i < carsArray.length; i++)
    {
        Imgproc.rectangle(matRGB,carsArray[i].tl(),carsArray[i].br(),CAR_RECT_COLOR,3);
        xCenter = (carsArray[i].x + carsArray[i].width + carsArray[i].x) / 2;
        yCenter = (carsArray[i].y + carsArray[i].y + carsArray[i].height) / 2;
        Point center = new Point(xCenter,yCenter);

        CurrentCars.add(center);

        Imgproc.putText(matRGB,"[" + center.x + "," + center.y + "]",new Point(center.x + 20,center.y + 20),Core.FONT_HERShey_SIMPLEX,0.7,new Scalar(255,255,255));

    }

    if (prevIoUsPoints.empty()){
        prevIoUsPoints.fromList(CurrentCars);
        matGray.copyTo(matPrevGray);
    }

    currentPoints = new MatOfPoint2f();
    MatOfByte status = new MatOfByte();
    MatOfFloat err = new MatOfFloat();
    TermCriteria criteria = new TermCriteria(TermCriteria.COUNT + TermCriteria.EPS,10,0.03);
    Video.calcopticalFlowPyrLK(matPrevGray,matGray,prevIoUsPoints,currentPoints,status,err);

    byte StatusArr[] = status.toArray();
    Point p0Arr[] = prevIoUsPoints.toArray();
    Point p1Arr[] = currentPoints.toArray();
    ArrayList<Point> good_new = new ArrayList<>();
    for (int i = 0; i<StatusArr.length ; i++ ) {
        if (StatusArr[i] == 1) {
            good_new.add(p1Arr[i]);
            Imgproc.line(matRGB,p1Arr[i],p0Arr[i],0),2);
            Imgproc.circle(matRGB,5,-1);
        }
    }

    currentPoints.copyTo(prevIoUsPoints);
    matGray.copyTo(matPrevGray);

解决方法

matPrevGray 为空。这就是它所说的。