Draw interactive points on an image

Hello guys,
i have a set of images, all of the same size (height and width), and for each image i have a set of coordinates (x,y) rapresenting interactive points i have to draw on the selected image.
Let's say i have image A with two points PointA(X=30 , y=60) ,PointB(X=60 , Y=10) and PointC(X=70,Y=70) like in the image i have attached:

https://s17.postimg.org/r46n2y8e7/cliccabili.jpg

Can you tell me how i could achieve my goal?With which instruments? Can you link me some examples?
Thank you for the answers and your time

You can load images using QImage.
You can draw on a QImage using QPainter.

Cheers,
_