OpenCV4入门154：kalman跟踪

索引地址：系列索引

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#include "opencv2/opencv.hpp"
#include <iostream>

using namespace std;
using namespace cv;

TermCriteria criteria(TermCriteria::MAX_ITER + TermCriteria::EPS, 20, 1.0);

bool  selecting = false;
Rect  selection;
Point spo; // selection point origin

void onMouse(int event, int x, int y, int, void *) {
    switch (event) {
        case EVENT_LBUTTONDOWN: {
            spo.x            = x;
            spo.y            = y;
            selection.x      = spo.x;
            selection.y      = spo.y;
            selection.width  = 0;
            selection.height = 0;
            selecting        = true;

        } break;
        case EVENT_LBUTTONUP: {
            selecting = false;
        } break;
        default: {
            selection.x      = min(x, spo.x);
            selection.y      = min(y, spo.y);
            selection.width  = abs(x - spo.x);
            selection.height = abs(y - spo.y);
        } break;
    }
}

int main() {
    VideoCapture cam(0);
    if (!cam.isOpened())
        return -1;

    KalmanFilter kalman(4, 2);

    Mat_<float> tm(4, 4); // transition matrix
    tm << 1, 0, 1, 0,     // next x = 1x+0y+1x'+0y'
        0, 1, 0, 1,       // next x'= 0x+1y+0x'+1y'
        0, 0, 1, 0,       // next y = 0x+0y+1x'+0y
        0, 0, 0, 1;       // next y'= 0x+0y+0x'+1y'
    kalman.transitionMatrix = tm;
    Mat_<float> pos(2, 1);
    pos.at<float>(0) = 0;
    pos.at<float>(1) = 0;

    kalman.statePre.at<float>(0) = 0; // init x
    kalman.statePre.at<float>(1) = 0; // init y
    kalman.statePre.at<float>(2) = 0; // init x'
    kalman.statePre.at<float>(3) = 0; // init y'

    setIdentity(kalman.measurementMatrix);

    setIdentity(kalman.processNoiseCov, Scalar::all(0.00001));

    Rect srchWnd;

    string outputWindow = "Display";
    namedWindow(outputWindow);
    cv::setMouseCallback(outputWindow, onMouse);

    Mat histogram, backProject, mask;

    int key = -1;
    while (key != ' ') {
        Mat frame;
        cam >> frame;
        if (frame.empty())
            break;

        Mat         frmHsv, hue;
        vector<Mat> hsvChannels;
        cvtColor(frame, frmHsv, COLOR_BGR2HSV);
        split(frmHsv, hsvChannels);
        hue = hsvChannels[ 0 ];

        int          bins       = 120;
        int          nimages    = 1;
        int          channels[] = {0};
        float        rangeHue[] = {0, 180};
        const float *ranges[]   = {rangeHue};
        int          histSize[] = {bins};
        bool         uniform    = true;

        if (selecting && selection.area() > 0) {
            Mat sel(frame, selection);

            int lbHue = 00, hbHue = 180;
            int lbSat = 30, hbSat = 256;
            int lbVal = 30, hbVal = 230;

            inRange(frmHsv, Scalar(lbHue, lbSat, lbVal), Scalar(hbHue, hbSat, hbVal), mask);

            Mat roi(hue, selection);
            Mat maskroi(mask, selection);

            calcHist(&roi, nimages, channels, maskroi, histogram, 1, histSize, ranges, uniform);

            normalize(histogram, histogram, 0, 255, NORM_MINMAX);

            bitwise_not(sel, sel);

            srchWnd = selection;
        } else if (!histogram.empty()) {

            double scale = 1.0;
            calcBackProject(&hue, nimages, channels, histogram, backProject, ranges, scale,
                            uniform);

            erode(backProject, backProject, Mat());

            //            meanShift(backProject,
            //                      srchWnd,
            //                      criteria);

            CamShift(backProject, srchWnd, criteria);

            Point objectPos(srchWnd.x + srchWnd.width / 2, srchWnd.y + srchWnd.height / 2);

            pos(0) = objectPos.x;
            pos(1) = objectPos.y;

            Mat estimation = kalman.correct(pos);
            kalman.predict();

            Point estPt(estimation.at<float>(0), estimation.at<float>(1));

            drawMarker(frame, estPt, Scalar(0, 255, 0), MARKER_CROSS, 30, 2);

            cvtColor(backProject, backProject, COLOR_GRAY2BGR);
            drawMarker(backProject, estPt, Scalar(0, 255, 0), MARKER_CROSS, 30, 2);
        }

        switch (key) {
            case 'b':
                if (!backProject.empty())
                    imshow(outputWindow, backProject);
                else
                    imshow(outputWindow, frame);
                break;
            case 'v':
            default:
                imshow(outputWindow, frame);
                break;
        }

        int k = waitKey(10);
        if (k > 0)
            key = k;
    }

    cam.release();

    return 0;
}