Question

我是opencv的新手。我试图检测特定图像中的车辆，如x = 0到139和y = 0到300的图像大小（300,400）。

那么我应该使用什么条件在特定区域检测它并在车辆进入框架后对车辆进行计数？

enter code herevoid processVideo(char* videoFilename) {
//create the capture object
`VideoCapture capture(videoFilename);
if(!capture.isOpened()){
    //error in opening the video input
    cerr << "Unable to open video file: " << videoFilename << endl;
    exit(EXIT_FAILURE);
}
//read input data. ESC or 'q' for quitting
while( (char)keyboard != 'q' && (char)keyboard != 27 ){
    //read the current frame
    if(!capture.read(frame)) {
        cerr << "Unable to read next frame." << endl;
        cerr << "Exiting..." << endl;
        exit(EXIT_FAILURE);
    }
    //update the background model
    pMOG2->apply(frame, fgMaskMOG2);
    Mat im_th, src_gray;
    cvtColor( frame, src_gray, COLOR_BGR2GRAY );
    medianBlur( fgMaskMOG2, fgMaskMOG2, 15 );
    threshold( fgMaskMOG2, im_th,230 , 255, THRESH_BINARY_INV);

        Mat im_floodfill = im_th.clone();
       floodFill(im_floodfill, cv::Point(0,0), Scalar(255));

       Mat im_floodfill_inv;
       bitwise_not(im_floodfill, im_floodfill_inv);
       fgMaskMOG2= im_floodfill_inv;

       dilate(fgMaskMOG2, fgMaskMOG2,Mat ());
       erode(fgMaskMOG2, fgMaskMOG2,Mat ());
       medianBlur( fgMaskMOG2, fgMaskMOG2, 15 );
       //adaptiveThreshold(fgMaskMOG2,fgMaskMOG2 ,255,ADAPTIVE_THRESH_GAUSSIAN_C,THRESH_BINARY,11,2);

               rectangle(frame, cv::Point(10, 2), cv::Point(100,20),
                         cv::Scalar(255,0,255), -1);

               stringstream ss;
               ss << capture.get(CAP_PROP_POS_FRAMES);
               string frameNumberString = ss.str();
               putText(frame, frameNumberString.c_str(), cv::Point(15, 15),
                       FONT_HERSHEY_SIMPLEX, 0.5 , cv::Scalar(0,0,0));
               //show the current frame and the fg masks
               imshow("Frame", frame);
               imshow("FG Mask MOG 2", fgMaskMOG2);

              vector<vector<Point> > contours;
               vector<Vec4i> hierarchy;

               findContours( fgMaskMOG2, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(0,0) );

               Mat drawing = frame;

                   Rect bounding_rect;

                   vector<Rect> boundRect( contours.size() );
                   vector<vector<Point> > contours_poly( contours.size() );


                   Scalar color( 255,0,0);  // color of the contour in the
                   //Draw the contour and rectangle


                   for( int i = 0; i < s; i++ )
                       { //approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true );
                       approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true );
                         boundRect[i] = boundingRect( Mat(contours_poly[i]) );

                       }
);

                   for( int i = 0; i< s; i++ )
                       {
                       drawContours( frame, contours_poly, i, color, 1, 8, vector<Vec4i>(), 0, Point() );
                       rectangle( frame, boundRect[i].tl(), boundRect[i].br(), color, 2, 8, 0 );
                       }
                   imshow( "Display window", frame);
               }

               keyboard = waitKey(39);
}

Answer 1

更改：

findContours( fgMaskMOG2, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, 
Point(0,0) );

要：

findContours( fgMaskMOG2(cv::Rect(x,y,width,height)), contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, 
Point(0,0) );

cv::Rect(x,y,width,height)表示投资回报率

如何使用opencv和C ++在特定图像区域中找到轮廓？

1 个答案: