I had a book with two-columns pages. I wanted cut every column of a page and then stick two columns vertically. This is a project for this task and some related tasks. I've listed this tasks below:
For each page first of all, we need to export page number from name of the page.
This function create two columns from a page.
This function cut a part of a page in the way we want.
This function merge two image vertically.
I wanted to export the txt of a book. I had pages of the book at image format and I wanted to convert these with an Iranian OCR system. But this system could not recognize two columns page correctly. So I should cut coulmns and merge these vertically. And this system wanted money for each page, so if I had fewer pages, I paid fewer. So I used this code to merged four pages in one page.