You need to install Apache server. Windows users can use wampserver and linux users can use xampp.
Add the contents of the repo to the www folder in your machine. Run Apache and make sure that http://localhost/annotation.html is accessible from the browser.
Move to the html directory in the repo.
Add the images of the pages to be annotated in the images/images folder.
Add the names of all these images in file_paths.txt.
Run sort_file_names.py to sort the file names. The sorted image names are stored in sorted_file_paths.txt.
Run python server.py --filename name where name is the destination to save the annotations. The file name can be used to denote what is being annotated - tables, figures, etc.
Go to http://localhost/annotation.html and you should see the first image for annotation.
Mark the annotation areas on the page using your mouse, you should be able to see the selected coordinates at the right bottom of the page.
Click 'N' to save these bounding boxes and move to the next page.
Click 'P' to reset the bounding boxes for the current image and start marking for the page again.