opencv点目标追踪

opencv点目标追踪

//--------------------------------【help( )函数】----------------------------------------------
// 描述：输出帮助信息
//-------------------------------------------------------------------------------------------------
static void help()
{
//输出欢迎信息和OpenCV版本
cout <<"\n\n\t\t\t非常感谢购买《OpenCV3编程入门》一书！\n"
<<"\n\n\t\t\t此为本书OpenCV2版的第10个配套示例程序\n"
<< "\n\n\t\t\t   当前使用的OpenCV版本为：" << CV_VERSION 
<<"\n\n  ----------------------------------------------------------------------------" ;
cout << "\n\n\t该Demo演示了 Lukas-Kanade基于光流的lkdemo\n";
cout << "\n\t程序默认从摄像头读入视频，可以按需改为从视频文件读入图像\n";
cout << "\n\t操作说明: \n"
"\t\t通过点击在图像中添加/删除特征点\n" 
"\t\tESC - 退出程序\n"
"\t\tr -自动进行追踪\n"
"\t\tc - 删除所有点\n"
"\t\tn - 开/光-夜晚模式\n"<< endl;
}
Point2f point;
bool addRemovePt = false;
//--------------------------------【onMouse( )回调函数】------------------------------------
// 描述：鼠标操作回调
//-------------------------------------------------------------------------------------------------
static void onMouse( int event, int x, int y, int /*flags*/, void* /*param*/ )
{
if( event == CV_EVENT_LBUTTONDOWN )
{
point = Point2f((float)x, (float)y);
addRemovePt = true;
}
}
//-----------------------------------【main( )函数】--------------------------------------------
// 描述：控制台应用程序的入口函数，我们的程序从这里开始
//-------------------------------------------------------------------------------------------------
int main( int argc, char** argv )
{
help();
VideoCapture cap;
TermCriteria termcrit(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS, 20, 0.03);
Size subPixWinSize(10,10), winSize(31,31);
const int MAX_COUNT = 500;
bool needToInit = false;
bool nightMode = false;
cap.open(0);
if( !cap.isOpened() )
{
cout << "Could not initialize capturing...\n";
return 0;
}
namedWindow( "LK Demo", 1 );
setMouseCallback( "LK Demo", onMouse, 0 );
Mat gray, prevGray, image;
vector<Point2f> points[2];
for(;;)
{
Mat frame;
cap >> frame;
if( frame.empty() )
break;
frame.copyTo(image);
cvtColor(image, gray, COLOR_BGR2GRAY);
if( nightMode )
image = Scalar::all(0);
if( needToInit )
{
// 自动初始化
goodFeaturesToTrack(gray, points[1], MAX_COUNT, 0.01, 10, Mat(), 3, 0, 0.04);
cornerSubPix(gray, points[1], subPixWinSize, Size(-1,-1), termcrit);
addRemovePt = false;
}
else if( !points[0].empty() )
{
vector<uchar> status;
vector<float> err;
if(prevGray.empty())
gray.copyTo(prevGray);
calcOpticalFlowPyrLK(prevGray, gray, points[0], points[1], status, err, winSize,
3, termcrit, 0, 0.001);
size_t i, k;
for( i = k = 0; i < points[1].size(); i++ )
{
if( addRemovePt )
{
if( norm(point - points[1][i]) <= 5 )
{
addRemovePt = false;
continue;
}
}
if( !status[i] )
continue;
points[1][k++] = points[1][i];
circle( image, points[1][i], 3, Scalar(0,255,0), -1, 8);
}
points[1].resize(k);
}
if( addRemovePt && points[1].size() < (size_t)MAX_COUNT )
{
vector<Point2f> tmp;
tmp.push_back(point);
cornerSubPix( gray, tmp, winSize, cvSize(-1,-1), termcrit);
points[1].push_back(tmp[0]);
addRemovePt = false;
}
needToInit = false;
imshow("LK Demo", image);
char c = (char)waitKey(10);
if( c == 27 )
break;
switch( c )
{
case 'r':
needToInit = true;
break;
case 'c':
points[0].clear();
points[1].clear();
break;
case 'n':
nightMode = !nightMode;
break;
}
std::swap(points[1], points[0]);
cv::swap(prevGray, gray);
}
return 0;
}