[quinnjh]

I don’t think people are suggesting : Build a renderer > build an ocr pipeline > run it on pdfs

I think people are suggesting : Use a readymade renderer > use readymade OCR pipelines/apis > run it on pdfs

A colleague uses a document scanner to create a pdf of a document and sends it to you

You must return the data represented in it retaining as much structure as possible

How would you proceed? Return just the metadata of when the scan was made and how?

Genuinely wondering

[throwaway4496]

You can use an existing readymade renderer to render into structured data instead of raster.

[kwon-young]

Just to illustrate this point, poppler [1] (which is the most popular pdf renderer in open source) has a little tool called pdf2cairo [2] which can render a pdf into a svg. This means you can delegate all pdf rendering to poppler and only work with actual graphical objects to extract semantics.

I think the reason this method is not popular is that there are still many ways to encode a semantic object graphically. A sentence can be broken down into words or letters. Table lines can be formed from multiple smaller lines, etc. But, as mentioned by the parent, rule based systems works reasonably well for reasonably focused problems. But you will never have a general purpose extractor since rules needs to be written by humans.

[1] https://poppler.freedesktop.org/ [2] https://gitlab.freedesktop.org/poppler/poppler/-/blob/master...

[throwaway4496]

There is also PDF to HTML, PDF to Text, MuPDF also has PDF to XML, both projects along with a bucketful of other PDF toolkits have PDF to PS, and there is many many XML, HTML, and Text outputs for PS.

Rastering and OCR'ing PDF is like using regex to parse XHTML. My eyes are starting to bleed out, I am done here.

[ramraj07]

It looks like you make a lot of valid points, but also have an extremely visceral reaction because theres a company out there thats using AI in a way that offends you. I mean fair still.

But im a guy who's in the market for a pdf parser service, im happy to pay pretty penny per page processed. I just want a service that works without me thinking for a second about any of the problems you guys are all discussing. What service do I use? Do I care if it uses AI in the lamest way possible? The only thing that matters are the results. There are two people including you in this thread ramming with pdf parsing gyan but from reading it all, it doesn't look like I can do things the right way without spending months fully immersed in this problem alone. If you or anyone has a non blunt AI service that I can use Ill be glad to check it out.

[throwaway4496]

It is a hard problem, yes, but you don't solve it by rastering it, OCR, and then using AI. You render it into a structured format. Then at least you don't have to worry about hallucinations, fancy fonts OCR problems, text shaping problems, huge waste of GPU and CPU to paint an image only to OCR it and throw it away.

Use a solution that renders PDF into structured data if you want correct and reliable data.

[anthk]

pdftotext from poppler has that without doing juggling with formats.