【OpenCV C++】彩色目标跟

程序说明

// 程序描述：来自OpenCV安装目录下Samples文件夹中的官方示例程序-彩色目标跟踪操作
// 示例路径：opencv\sources\samples\cpp\camshiftdemo.cpp
// 操作系统： Windows 10 64bit
// 开发语言： C++
// IDE 版 本：Visual Studio 2019
// OpenCV版本：4.20

代码

#include <opencv2/core/utility.hpp>
#include "opencv2/video/tracking.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/videoio.hpp"
#include "opencv2/highgui.hpp"

#include <iostream>
#include <ctype.h>

using namespace cv;
using namespace std;

//-----------------------------------【全局变量声明】-----------------------------------------
//		描述：声明全局变量
//
Mat image;
bool backprojMode = false;
bool selectObject = false;
int trackObject = 0;
bool showHist = true;
Point origin;
Rect selection;
int vmin = 10, vmax = 256, smin = 30;

//--------------------------------【onMouse( )回调函数】------------------------------------
//		描述：鼠标操作回调
//-------------------------------------------------------------------------------------------------
// User draws box around object to track. This triggers CAMShift to start tracking
static void onMouse(int event, int x, int y, int, void*)
{
    if (selectObject)
    {
        selection.x = MIN(x, origin.x);
        selection.y = MIN(y, origin.y);
        selection.width = std::abs(x - origin.x);
        selection.height = std::abs(y - origin.y);

        selection &= Rect(0, 0, image.cols, image.rows);
    }

    switch (event)
    {
    case EVENT_LBUTTONDOWN:
        origin = Point(x, y);
        selection = Rect(x, y, 0, 0);
        selectObject = true;
        break;
    case EVENT_LBUTTONUP:
        selectObject = false;
        if (selection.width > 0 && selection.height > 0)
            trackObject = -1;   // Set up CAMShift properties in main() loop
        break;
    }
}


//--------------------------------【help( )函数】----------------------------------------------
//		描述：输出帮助信息
//-------------------------------------------------------------------------------------------------
string hot_keys =
"\n\nHot keys: \n"
"\tESC - quit the program - 退出程序\n"
"\tc - stop the tracking - 停止追踪\n"
"\tb - switch to/from backprojection view - 开/关-投影视图\n"
"\th - show/hide object histogram - 显示/隐藏-对象直方图\n"
"\tp - pause video - 暂停视频\n"
"To initialize tracking, select the object with mouse\n";

static void help()
{
    cout << "\nThis is a demo that shows mean-shift based tracking\n"
        "You select a color objects such as your face and it tracks it.\n"
        "This reads from video camera (0 by default, or the camera number the user enters\n"
        "Usage: \n"
        "   ./camshiftdemo [camera number]\n";

    cout << hot_keys;
}

const char* keys =
{
    "{help h | | show help message}{@camera_number| 0 | camera number}"
};

int main(int argc, const char** argv)
{
    VideoCapture cap;
    Rect trackWindow;
    int hsize = 16;
    float hranges[] = { 0,180 };
    const float* phranges = hranges;
    CommandLineParser parser(argc, argv, keys);
    if (parser.has("help"))
    {
        help();
        return 0;
    }
    // int camNum = parser.get<int>(0);
    // cap.open(camNum);
   cap.open("0.mp4");
    if (!cap.isOpened())
    {
        help();
        cout << "***Could not initialize capturing...***\n";
        cout << "Current parameter's value: \n";
        parser.printMessage();
        return -1;
    }

    cout << "\n\n\t此Demo显示了基于均值漂移的追踪（tracking）技术\n"
        "\t请用鼠标框选一个有颜色的物体，对它进行追踪操作\n";

    cout << hot_keys;
    namedWindow("Histogram", 0);
    namedWindow("CamShift Demo", 0);
    setMouseCallback("CamShift Demo", onMouse, 0);
    createTrackbar("Vmin", "CamShift Demo", &vmin, 256, 0);
    createTrackbar("Vmax", "CamShift Demo", &vmax, 256, 0);
    createTrackbar("Smin", "CamShift Demo", &smin, 256, 0);

    Mat frame, hsv, hue, mask, hist, histimg = Mat::zeros(200, 320, CV_8UC3), backproj;
    bool paused = false;

    for (;;)
    {
        if (!paused)
        {
            cap >> frame;
            if (frame.empty())
                break;
        }

        frame.copyTo(image);

        if (!paused)
        {
            cvtColor(image, hsv, COLOR_BGR2HSV);

            if (trackObject)
            {
                int _vmin = vmin, _vmax = vmax;

                inRange(hsv, Scalar(0, smin, MIN(_vmin, _vmax)),
                    Scalar(180, 256, MAX(_vmin, _vmax)), mask);
                int ch[] = { 0, 0 };
                hue.create(hsv.size(), hsv.depth());
                mixChannels(&hsv, 1, &hue, 1, ch, 1);

                if (trackObject < 0)
                {
                    // Object has been selected by user, set up CAMShift search properties once
                    Mat roi(hue, selection), maskroi(mask, selection);
                    calcHist(&roi, 1, 0, maskroi, hist, 1, &hsize, &phranges);
                    normalize(hist, hist, 0, 255, NORM_MINMAX);

                    trackWindow = selection;
                    trackObject = 1; // Don't set up again, unless user selects new ROI

                    histimg = Scalar::all(0);
                    int binW = histimg.cols / hsize;
                    Mat buf(1, hsize, CV_8UC3);
                    for (int i = 0; i < hsize; i++)
                        buf.at<Vec3b>(i) = Vec3b(saturate_cast<uchar>(i * 180. / hsize), 255, 255);
                    cvtColor(buf, buf, COLOR_HSV2BGR);

                    for (int i = 0; i < hsize; i++)
                    {
                        int val = saturate_cast<int>(hist.at<float>(i) * histimg.rows / 255);
                        rectangle(histimg, Point(i * binW, histimg.rows),
                            Point((i + 1) * binW, histimg.rows - val),
                            Scalar(buf.at<Vec3b>(i)), -1, 8);
                    }
                }

                // Perform CAMShift
                calcBackProject(&hue, 1, 0, hist, backproj, &phranges);
                backproj &= mask;
                RotatedRect trackBox = CamShift(backproj, trackWindow,
                    TermCriteria(TermCriteria::EPS | TermCriteria::COUNT, 10, 1));
                if (trackWindow.area() <= 1)
                {
                    int cols = backproj.cols, rows = backproj.rows, r = (MIN(cols, rows) + 5) / 6;
                    trackWindow = Rect(trackWindow.x - r, trackWindow.y - r,
                        trackWindow.x + r, trackWindow.y + r) &
                        Rect(0, 0, cols, rows);
                }

                if (backprojMode)
                    cvtColor(backproj, image, COLOR_GRAY2BGR);
                ellipse(image, trackBox, Scalar(0, 0, 255), 3, LINE_AA);
            }
        }
        else if (trackObject < 0)
            paused = false;

        if (selectObject && selection.width > 0 && selection.height > 0)
        {
            Mat roi(image, selection);
            bitwise_not(roi, roi);
        }

        imshow("CamShift Demo", image);
        imshow("Histogram", histimg);

        char c = (char)waitKey(10);
        if (c == 27)
            break;
        switch (c)
        {
        case 'b':
            backprojMode = !backprojMode;
            break;
        case 'c':
            trackObject = 0;
            histimg = Scalar::all(0);
            break;
        case 'h':
            showHist = !showHist;
            if (!showHist)
                destroyWindow("Histogram");
            else
                namedWindow("Histogram", 1);
            break;
        case 'p':
            paused = !paused;
            break;
        default:
            ;
        }
    }

    return 0;
}

操作描述与运行效果

操作指南如图所示