Predit a point position with the Homography matrix

1

Hello,
After computing the Homography transform with
Mat h = findHomography(pts_src, pts_dst);

I want to predict the position of only one point from the source image to the destination image.
How to use the Homography matrix to compute this only one point?
Thank you

2

what have you tried?

3 
perspectiveTransform( obj, obj_projection, homography_matrix);
for(std::size_t i=0;i<obj_projection.size();i++)
{
    std::cout<<obj_projection.at(i).x <<"," <<obj_projection.at(i).y<<std::endl;
}