How to crop part of the image between specified lines in opencv?

I’m currently working on implementation in python the algorithm presented in [1611.03270] Detecting Moving Regions in CrowdCam Images. In the following paper there is a part when we create epipolar lines and we want to take part of the image between those lines. Creation of the lines is fairly easy and it can be done with approach presented for instance here OpenCV: Epipolar Geometry. I tried to find a solution that would get me a part of the image between those lines (with some set width) but I couldn’t find any. I know that I could manually take values from pixels via calculating if they are under/above lines but maybe there is a more elegant solution to this problem? Do you guys have any idea or maybe experienced similar problem in the past?