如何使用Python将图像中的轮廓(矩形)替换为新的图像?

I'm currently using the opencv (CV2) and Python Pillow image library to try and take an image of arbitrary phones and replace the screen with a new image. I've gotten to the point where I can take an image and identify the screen of the phone and get all the coordinates for the corner, but I'm having a really hard time replacing that area in the image with a new image.I'm currently using the opencv (CV2) and Python