Opencv and drawing roi on mat

x3rv1th

Hi...

I try to draw a ROI (region of interest) on Mat with QMouseEvent and display it on QLabel.

Got slot like this :
@
void mDisplay::draw_ROI(int& r1,int& r2,QPoint& position, cv::Mat& matsROI)
{

cv::Mat matfROI;
matsROI.copyTo(matfROI);

cv::Rect rectang = cv::Rect(r1,r2,position.x()-r1,position.y()-r2);
cv::rectangle(matfROI,rectang,cv::Scalar(0,255,0),1,8,0);

this->ShowMat(matfROI);

matfROI.release();

}

@

When mouseMoveEvent is triggered it emits signal with position of left button click (int& r1,int& r2) which works perfect,actual cursor position (QPoint& position) and matrix with picture (cv::Mat& matsRoi).All of that works great.
The only problem is,that when I move cursor over QLabel, rectangle is drawn on same image which results in many rectangles.
Shouldn't matfROI be copied again on every mouse move?

I also declared int test = 0 just under declaration of matsROI and added to this slot
@
int c = test;

c+=5;

qDebug()<<c<<endl;
@

and it always shows 5 as expected,so why mat is not copied on each mouse move?

PS. Tried to place this piece of code directly in mouseMoveEvent,but got same issue.

Thanks in advance!