Diff-pdf: tool to visually compare two PDFs • Hacker News Board

Re: Diff-pdf: tool to visually compare two PDFs

#11

Post by jgalt212 » Tue, Jul 02, 2024, 12:00 PM UTC

Thanks. I'll give this a shot to see if any counterparties try to sneak in any last second changes to the executable version of the doc.

Re: Diff-pdf: tool to visually compare two PDFs

#12

Post by infecto » Tue, Jul 02, 2024, 12:15 PM UTC

canistel wrote: post #4

Interestingly, Github thinks the project is 46% shell, due to the fairly huge wxwin.m4.

I noticed this a while back with a private project of mine. The Github languages breakdown seems broken. Mine is a Python project with a handful of Jupyter notebooks but many many python files. The LOC must be 80% python files but Github sees the project as 50% Jupyter.

Re: Diff-pdf: tool to visually compare two PDFs

#13

Post by infecto » Tue, Jul 02, 2024, 12:18 PM UTC

asah wrote: post #8

Crazy, I'd have thought that modern multi-modal LLMs can do this, but when I tried Gemini, ChatGPT-4o and Claude they all pooped out: - Gemini at first only diff'd the text, and then when pushed it identified the items in the images and then hallucinated the differences between the versions. It could not produce an image output. - Claude only diff'd the text and refused to believe that there images in the PDFs. - Cha…

This is definitely not a strength for multi-modal LLM. Multi-modal capabilities are still too flaky especially when looking at a page of a PDF which can have multiple areas of focus.

Re: Diff-pdf: tool to visually compare two PDFs

#14

Post by akasakahakada » Tue, Jul 02, 2024, 12:36 PM UTC

Use this to compare university textbook edition 8 and 9 before buying.

Re: Diff-pdf: tool to visually compare two PDFs

#15

Post by smartmic » Tue, Jul 02, 2024, 12:39 PM UTC

I like this tool better: https://www.qtrac.eu/diffpdf.html

It shows the differences in the GUI side-by-side instead of overlayed.

Re: Diff-pdf: tool to visually compare two PDFs

#16

Post by ertgbnm » Tue, Jul 02, 2024, 12:43 PM UTC

asah wrote: post #8

Crazy, I'd have thought that modern multi-modal LLMs can do this, but when I tried Gemini, ChatGPT-4o and Claude they all pooped out: - Gemini at first only diff'd the text, and then when pushed it identified the items in the images and then hallucinated the differences between the versions. It could not produce an image output. - Claude only diff'd the text and refused to believe that there images in the PDFs. - Cha…

This may be the type of thing that LLMs are currently the worst at. I'm not surprised at all.

Re: Diff-pdf: tool to visually compare two PDFs

#17

Post by [deleted] » Tue, Jul 02, 2024, 12:47 PM UTC

Levitating wrote: post #6

No screenshots?

[deleted]

Re: Diff-pdf: tool to visually compare two PDFs

#18

Post by ant6n » Tue, Jul 02, 2024, 12:48 PM UTC

akasakahakada wrote: post #14

Use this to compare university textbook edition 8 and 9 before buying.

Uh how can you compare without buying? Or put another way, why buy if you can compare?

Re: Diff-pdf: tool to visually compare two PDFs

#19

Post by invalidlogin » Tue, Jul 02, 2024, 12:51 PM UTC

smartmic wrote: post #15

I like this tool better: https://www.qtrac.eu/diffpdf.html It shows the differences in the GUI side-by-side instead of overlayed.

I use BeyondCompare 5 for this.

Re: Diff-pdf: tool to visually compare two PDFs

#20

Post by pmarreck » Tue, Jul 02, 2024, 1:01 PM UTC

thibaut_barrere wrote: post #9

I have been using this in a CI pipeline to maintain a business-critical PDF generation (healthcare) app (started circa 2010 I think), here is the RSpec helpers I'm using: https://gist.github.com/thbar/d1ce2afef68bf6089aeae8d9ddc05d... The code contains git-stored reference PDFs, and the test suite re-generate them and assert that nothing has changed. Helped a lot to audit visual changes, or PDF library upgrades!

could you not just compare the source (or perhaps even the hash) of the PDF and assert on that?