模板与模板更新匹配

我正在尝试使用OpenCV/C++中的模板实现实时跟踪。我面临着用每一帧更新模板的问题。

以下是代码：

#include <iostream>
#include "opencv2/opencv.hpp"
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/objdetect/objdetect.hpp>
#include <sstream>

using namespace cv;
using namespace std;
Point point1, point2; /* vertical points of the bounding box */
int drag = 0;
Rect rect; /* bounding box */
Mat img, roiImg; /* roiImg - the part of the image in the bounding box */
int select_flag = 0;
bool go_fast = false;
Mat mytemplate;

///------- template matching -----------------------------------------------------------------------------------------------
Mat TplMatch( Mat &img, Mat &mytemplate )
{
  Mat result;
  matchTemplate( img, mytemplate, result, CV_TM_SQDIFF_NORMED );
  normalize( result, result, 0, 1, NORM_MINMAX, -1, Mat() );
  return result;
}

///------- Localizing the best match with minMaxLoc ------------------------------------------------------------------------
Point minmax( Mat &result )
{
  double minVal, maxVal;
  Point  minLoc, maxLoc, matchLoc;
  minMaxLoc( result, &minVal, &maxVal, &minLoc, &maxLoc, Mat() );
  matchLoc = minLoc;
  return matchLoc;
}

///------- tracking --------------------------------------------------------------------------------------------------------
void track()
{
    if (select_flag)
    {
        roiImg.copyTo(mytemplate);
//         select_flag = false;   //select_flag is kept false so that new template can
        go_fast = true;           //copied to 'mytemplate' for each iteration
    }
//     imshow( "mytemplate", mytemplate ); waitKey(0);
    Mat result  =  TplMatch( img, mytemplate );
    Point match =  minmax( result );  //PROBLEM: "match" always returning same value!!!
    rectangle( img, match, Point( match.x + mytemplate.cols , match.y + mytemplate.rows ), CV_RGB(255, 255, 255), 0.5 );
    std::cout << "match: " << match << endl;
    /// template update step
    Rect ROI = cv::Rect( match.x, match.y, mytemplate.cols, mytemplate.rows );
    roiImg = img( ROI );
    imshow( "roiImg", roiImg ); //waitKey(0);
}

///------- MouseCallback function ------------------------------------------------------------------------------------------
void mouseHandler(int event, int x, int y, int flags, void *param)
{
    if (event == CV_EVENT_LBUTTONDOWN && !drag)
    {
        /// left button clicked. ROI selection begins
        point1 = Point(x, y);
        drag = 1;
    }
    if (event == CV_EVENT_MOUSEMOVE && drag)
    {
        /// mouse dragged. ROI being selected
        Mat img1 = img.clone();
        point2 = Point(x, y);
        rectangle(img1, point1, point2, CV_RGB(255, 0, 0), 3, 8, 0);
        imshow("image", img1);
    }
    if (event == CV_EVENT_LBUTTONUP && drag)
    {
        point2 = Point(x, y);
        rect = Rect(point1.x, point1.y, x - point1.x, y - point1.y);
        drag = 0;
        roiImg = img(rect);
    }
    if (event == CV_EVENT_LBUTTONUP)
    {
        /// ROI selected
        select_flag = 1;
        drag = 0;
    }
}

///------- Main() ----------------------------------------------------------------------------------------------------------
int main()
{
    int k;
    ///open video file
    VideoCapture cap;
    cap.open( "Megamind.avi" );
    if ( !cap.isOpened() )
    {   cout << "Unable to open video file" << endl;    return -1;    }
    cap >> img;
    GaussianBlur( img, img, Size(7,7), 3.0 );
    imshow( "image", img );
    while (1)
    {
        cap >> img;
        if ( img.empty() )
            break;
        // Flip the frame horizontally and add blur
        cv::flip( img, img, 1 );
        GaussianBlur( img, img, Size(7,7), 3.0 );
        if ( rect.width == 0 && rect.height == 0 )
            cvSetMouseCallback( "image", mouseHandler, NULL );
        else
            track();
        imshow("image", img);
        k = waitKey(go_fast ? 30 : 10000);
        if (k == 27)
            break;
    }
    return 0;
}

未跟踪更新的模板。我不知道为什么会发生这种情况，因为我每次迭代都在更新我的模板（roiImg）。minmax（）函数的match值每次都返回相同的值（坐标）。测试视频可在以下网址获取：Megamind请仔细观察并指引前方。。。非常感谢！

编辑：如果您运行代码（与视频一起），您将看到白色边界框始终位于同一位置。这是因为，minmax（）始终返回相同的"匹配"值。此值应随每次更新而更改。尝试运行select_flag＝false的代码（未提交）。边界框正在根据模板移动。但在这种情况下，不会进行模板更新。