Apply black-and-white binary scale to pdf. (not grayscale)

When opened for the first time:

$ pip install pdf2img  
$ pip install img2pdf  
$ pip install opencv-python  

Windows users will also have to build or download poppler for Windows.
Download here: https://github.com/oschwartz10612/poppler-windows/releases/
After you unpack it, add the "bin/" folder to PATH
How to add folders to PATH: https://www.architectryan.com/2018/03/17/add-to-the-path-on-windows-10/

FOR EVERYONE:

You can adjust the threshold by changing the first number in brackets in line 39 (with higher values more content will result black)
I am glad to recieve your feedback about this project.
Enjoy :3