How to make polygon transparent in c++?

C++
1

Hello, I was just wondering if anyone knew how to make a polygon transparent in OpenCV c++? The code below is what I have already.

vector<Point> myPoly={Point(100,200), Point(100,100), Point(200,100), Point(200,200)};
vector<vector<Point>> contours = {myPoly}; //stores poly as a vector of poly's
 drawContours(Frame, contours, 0, Scalar(0,255,0),-1);

Thank you in advance. :yum: :slightly_smiling_face:

2

Just compute the average with the original image:

Mat FrameOrig,result;
Frame.copyTo(FrameOrig);
drawContours(Frame, contours, 0, Scalar(0,255,0),-1);
double transparency=0.5; //...or the desired value
addWeighted(Frame,transparency,FrameOrig,(1-transparency),0,result);
3

It works thank you very much