OpenCV 帧差法运动物体追踪

opencv 评论

最近迷上了物体跟踪的玩意,于是乎找了好多视频去看，翻来覆去呢就是用到了轮廓检测的api，还有耐心的不断的调试。

原理呢是帧差法（就是一帧一帧的比较）非HSV分离
看看视频 软件的工作流程

代码呢，emmm，真的是不好理解。

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#include<opencv2/opencv.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv/cv.h>
#include<opencv/highgui.h>

using namespace std;
using namespace cv;

const static int SEAITVITV_VALUE = 20; //阈值操作的起始范围 可手动调试
const static int BLUR_SIZE = 10;//blur 滤波Size大小

int theObject[2] = { 0,0 };//发现目标的坐标 x,y

Rect objectBoundingRect = Rect(0, 0, 0, 0);//目标跳动的矩形

string intTostring(int num)
{
//int 类型 转为 string
stringstream ss;
ss << num;
return ss.str();
}

void searchForMovement(Mat thresgoldImage, Mat &cameraFeed)
{    //寻找移动物

Mat temp;
bool objectDetected;
//形参的阈值图像传给中间变量
thresgoldImage.copyTo(temp);
//向量 用来存放轮廓点坐标 Point
vector < vector<Point> > contours;
//向量 用来存放层次
vector<Vec4i> hierarchy;
//调用api 来获取层次和轮廓点
findContours(temp, contours, hierarchy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);
//判断轮廓点的个数是否为0
if (contours.size() > 0) objectDetected = true;
else {
    objectDetected = false; 
}

if (objectDetected)
{
    //找最大的轮廓点
    vector<vector<Point> > largesContours;
    largesContours.push_back(contours.at(contours.size() - 1));
    objectBoundingRect = boundingRect(largesContours.at(0));
    //约找出接近中心位置的点
    int xpos = objectBoundingRect.x + objectBoundingRect.width / 2;
    int ypos = objectBoundingRect.y + objectBoundingRect.width / 2;
    //传给全局变量暂放坐标
    theObject[0] = xpos; theObject[1] = ypos;

}
int x = theObject[0];
int y = theObject[1];
//画一个圆圈
circle(cameraFeed, Point(x, y), 20, Scalar(0, 255, 0), 2);
//画十字架
line(cameraFeed, Point(x, y), Point(x, y - 25),Scalar(0,255,0),2);
line(cameraFeed, Point(x, y), Point(x, y + 25), Scalar(0, 255, 0), 2);
line(cameraFeed, Point(x, y), Point(x-25, y ), Scalar(0, 255, 0), 2);
line(cameraFeed, Point(x, y), Point(x+25, y ), Scalar(0, 255, 0), 2);
//输出坐标
putText(cameraFeed, "tracking at:(" + intTostring(x) + "," + intTostring(y) + ")", Point(x, y), 1, 1, Scalar(0, 255, 0));
}

int  main()
{
//按键是否调试
bool debugMode = false;
//按键是否跟踪
bool trackingEnable = false;
//是否暂停视频
bool pause = false;
//视频取帧的frame1 frame2
Mat frame1, frame2;
//上者灰度图像
Mat gray1, gray2;
//两者的不同图像
Mat differenceImg;
//视频类
VideoCapture capture;
//阈值后的图像
Mat thres;
while (1)//不断的播放视频 进行调试
{
    capture.open("3.mp4");
    if (!capture.isOpened())
    {
        //打开视频失败
        return -2;
    }
    //int total = capture.get(CV_CAP_PROP_FRAME_COUNT);
    //cout << total << endl;
    //获取当前帧 与总帧进行比较 从而循环
    while (capture.get(CV_CAP_PROP_POS_FRAMES) < capture.get(CV_CAP_PROP_FRAME_COUNT) - 1)
    {
        //捕获frame1
        capture.read(frame1);
        //转为灰度图
        cvtColor(frame1, gray1, COLOR_BGR2GRAY);
        //捕获frame2
        capture.read(frame2);
        //转为灰度图
        cvtColor(frame2, gray2, COLOR_BGR2GRAY);
        //调用api 找出两者不同的区域 存入differenceImg
        absdiff(gray1, gray2, differenceImg);
        //阈值操作
        threshold(differenceImg, thres, SEAITVITV_VALUE, 255, THRESH_BINARY);
        //滤波 去噪点
        blur(thres, thres, Size(BLUR_SIZE, BLUR_SIZE));
        //再进行一遍阈值
        threshold(thres, thres, SEAITVITV_VALUE, 255, THRESH_BINARY);
        //是否进入调试模式
            if (debugMode == true) {
            imshow("thres", thres);
            }
            else {
                //销毁窗口
                destroyWindow("thres");
            }
            //是否进入追踪捕获模式
            if (trackingEnable) {
                searchForMovement( thres, frame1);
            }
            //显示原图像
            imshow("frame", frame1);
        switch (waitKey(50))
        {
        case 27:
            return 0;
        case 't':
        case 'T':
        {
            trackingEnable = !trackingEnable;
        if (trackingEnable == false) cout << "没有捕获" << endl;
        else cout << "捕获开始" << endl;
        break; 
        }
        case 'd':
        case 'D':
        {
            debugMode = !debugMode;
        if (debugMode == false) cout << "调试模式退出\n";
        else cout << "进入调试模式" << endl;
        break; 
        }
        case 112:
            pause = !pause;
            if (pause == true)
            {
                cout << "暂停" << endl;
                while (pause == true)
                {
                    switch (waitKey())
                    {
                    case 112:
                        pause = false;
                        break;
                    }
                }
            }
            else cout << "开始" << endl;
            break;
        }
    }
    //播放完后释放类
    capture.release();
}
}

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