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Show HN: HTML visualization of a PDF file's internal structure

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Re: Show HN: HTML visualization of a PDF file's internal structure

#41

Post by jimjimjim »

nabaraz wrote: post #39

On a similar note, why haven't PDF been replaced? There are XPS, DjVu and XHTML (EPUB) but they all seem to be targeting different usecase (a packaged HTML file). What I want is a simple document format that allows embedding other files and metadata without the Adobe's bloat. I should be able to hyperlink within pages, change font-size etc without text overflowing and being able to print in a consistent manner.

Different use cases.

"without text overflowing" brings with it a lot of detail. In pdf every letter/character/glyph of text can have an exact x,y position on the page (or off the page sometimes). This allows for precise positioning of content regardless of what else is going on. It is up to the application that writes the pdf to position things correctly and implement letter or word wrapping.

XPS was the closest to reimplementing PDF but microsoft didn't get enough buy in from other parties so it quietly died.

Re: Show HN: HTML visualization of a PDF file's internal structure

#42

Post by stronglikedan »

nabaraz wrote: post #39

On a similar note, why haven't PDF been replaced? There are XPS, DjVu and XHTML (EPUB) but they all seem to be targeting different usecase (a packaged HTML file). What I want is a simple document format that allows embedding other files and metadata without the Adobe's bloat. I should be able to hyperlink within pages, change font-size etc without text overflowing and being able to print in a consistent manner.

One reason is that none of those other formats are suitable for commercial printing as-is.

Re: Show HN: HTML visualization of a PDF file's internal structure

#43

Post by elliottcarlson »

ddulaney wrote: post #8
est wrote: post #5

I remember there was a similar project on github allows visualize any type of binary data by a given schema. There was an TCP/IP example IIRC.

https://kaitai.io/ maybe? It looks perfectly nice for its role, but I didn’t use it for my last project because I need serialization as well.

Kaitai is very useful for reverse engineering a binary file that you have some assumptions of. I've used it for save file reverse engineering and then creating a read/write library for it. It should be usable for PDF Metadata.

Re: Show HN: HTML visualization of a PDF file's internal structure

#44

Post by themanmaran »

bob1029 wrote: post #37
codetrotter wrote: post #26

Many moons ago I was tasked with extracting data from a bunch of PDFs. I made a tool to visualise how characters were laid out on the page and bounding boxes of all the elements. The project was in the end a complete failure and several people were upset at me for not delivering what I was supposed to. In present day, with the capabilities that are now available with LLMs to extract data from PDFs I 100% would go the…

Parsing data out of arbitrary PDFs is a cursed mission. PDF can contain images, so you might as well target JPEG directly. OCR can take you pretty far depending on expectations, but it's never quite far enough in my experience.

That's been our experience as well. Just scrapping any of the metadata associated with the PDF and treating it like an image. Since you never know when a document has a screenshot of an excel table inside.

The .NORM files (https://xkcd.com/2116)

Re: Show HN: HTML visualization of a PDF file's internal structure

#45

Post by xp84 »

nabaraz wrote: post #39

On a similar note, why haven't PDF been replaced? There are XPS, DjVu and XHTML (EPUB) but they all seem to be targeting different usecase (a packaged HTML file). What I want is a simple document format that allows embedding other files and metadata without the Adobe's bloat. I should be able to hyperlink within pages, change font-size etc without text overflowing and being able to print in a consistent manner.

I don't think what makes PDF an 'unfortunate' format for (1) editing, (2) on-device reading, and (3) extraction of semantic information (as opposed to presentational information) is any sin on Adobe's part nor 'bloat.'

It's a page description format, not a data format, so all its decisions follow from the need to ensure that you and I can both print the same 'page' even if we use different operating systems, software, printers, exact paper dimensions, etc. I suspect the main reason it holds on so well is that so many things operate in a document paradigm, where 'document' means 'collection of sheets of paper.' Everything from the After-Visit Summary from the doctor, to your car registration document already has a specific visual representation chosen to allow them to fit sensibly and precisely on sheets of paper.

Could HTML (say, with data URLs for its images and CSS so that it can stand on its own), or ePub be a better format in most ways? Sort of, but it is optimized for such a different goal that if you went in to evangelize that switch to everyone who makes PDFs today, you'd be met with frustration that the content will look a bit different on every device, and that depending on settings, even the page breaks would fall differently.

Relatedly, it's interesting to me that even Google Docs, which I suspect are printed or converted to PDF far less than half the time, defaults to the "paged" mode (see Page Setup) that shows document page borders and margins, instead of the far more useful "Pageless" mode which is more like a normal webpage that fits to window and scrolls one continuous surface endlessly.

Re: Show HN: HTML visualization of a PDF file's internal structure

#46

Post by brailsafe »

kohbo wrote: post #32
tekkk wrote: post #17

This would be really nice as browser library. Could just dragn drop a file and see its insides. But impressive nonetheless.

Do you mean a browser extension? Not trying to be rude; Just making sure I understand.

Since it's a python library, my guess is that they meant a JavaScript or WebAssembly package would be useful.

Re: Show HN: HTML visualization of a PDF file's internal structure

#47

Post by idislikelatex »

nabaraz wrote: post #39

On a similar note, why haven't PDF been replaced? There are XPS, DjVu and XHTML (EPUB) but they all seem to be targeting different usecase (a packaged HTML file). What I want is a simple document format that allows embedding other files and metadata without the Adobe's bloat. I should be able to hyperlink within pages, change font-size etc without text overflowing and being able to print in a consistent manner.

Because as soon as this conversation starts, the LaTeX crowd shows up, and everyone who something meaningful to add as a standard is blocked by that discussion.

Re: Show HN: HTML visualization of a PDF file's internal structure

#49

Post by staplung »

nabaraz wrote: post #39

On a similar note, why haven't PDF been replaced? There are XPS, DjVu and XHTML (EPUB) but they all seem to be targeting different usecase (a packaged HTML file). What I want is a simple document format that allows embedding other files and metadata without the Adobe's bloat. I should be able to hyperlink within pages, change font-size etc without text overflowing and being able to print in a consistent manner.

An interesting aspect of PDFs that I didn't know until quite recently is that they're a subset of PostScript and that in fact accounts for some of the heftiness. PostScript is a full-on programming language (albeit an unusual one) but PDFs are not (i.e. they're not Turing complete). They do not support control flow and what could be expressed as a simple loop in PS must be unrolled and stored as a series of simple declarations/expressions for a PDF.

The advantage is that PDFs don't need a full program interpreter to be rendered.

Re: Show HN: HTML visualization of a PDF file's internal structure

#50

Post by aboardRat4 »

codetrotter wrote: post #26

Many moons ago I was tasked with extracting data from a bunch of PDFs. I made a tool to visualise how characters were laid out on the page and bounding boxes of all the elements. The project was in the end a complete failure and several people were upset at me for not delivering what I was supposed to. In present day, with the capabilities that are now available with LLMs to extract data from PDFs I 100% would go the…

mathpix does quite an awesome job actually
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