How to do layout analysis/classification for invoice data extraction

I am developing a invoice data extraction using ocr and named entity recognition but some invoices have text arranged top to bottom and ocr reads line by line which makes it difficult to get Bill to details or ship to details. I searched and found that we can do layout analysis/classification to get region of interest. Can someone share any example or sample how to mark regions for better results as I am confused do i need to mark every …

analysis bill classification data data extraction deeplearning extraction found invoice line ocr recognition text