5 ms·
One of the challenges I have with RAG is excluding table of contents, headers/footers and appendices from PDFs. Is there a tool/technique to achieve this? I’m
by Oras 2y ago
One of the challenges I have with RAG is excluding table of contents, headers/footers and appendices from PDFs.
Is there a tool/technique to achieve this? I’m aware that I can use LLMs to do so, or read all pages and find identical text (header/footer), but I want to keep the page number as part of the metadata to ensure better citation on retrieval.
- prsdm 2y agoThis might help you: https://github.com/langchain-ai/langchain/blob/master/cookbook/Semi_Structured_RAG.ipynb https://github.com/langchain-ai/langchain/blob/master/cookbo...
- Oras 2y agoThank you, this is a mix of OCR and LLM, I was thinking if there might be a library to avoid using that. A better approach will be using Textract as it maintains the flow, such as if you have a table going across multiple pages. Btw, tesseract is not that good in getting accurate data from tables. Use it with caution especially in financial context. I have made an open source tool to show missing data from tesseract and easy ocr https://github.com/orasik/parsevision/ https://github.com/orasik/parsevision/
- prsdm 2y agoNice I really liked it!
- jonathan-adly 2y agoI would check out vision models as a technique to go around OCR errors. ColPali is the standard implementation & SOTA. Much better than OCR. We maintain a ready to go retrieval API that implements this: https://github.com/tjmlabs/ColiVara https://github.com/tjmlabs/ColiVara
- throwup238 2y agoYou’ll need other heuristics for ToC and indices but headers/footers are easy to detect via n-gram deduplication. You’ll want to figure out some rolling logic to handle chapter changes though.
- ellisv 2y agoHeaders/footers are also positional.