Show HN: PDF-Diff - Visualize any differences between two PDFs • Hacker News Board

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#11

Post by dloss » Sat, Aug 06, 2022, 1:33 PM UTC

i-net PDFC is my favorite tool in this space (after having tried a dozen others). Awesome features, multi-platform. Free trial version and an online demo available. https://www.inetsoftware.de/products/pdf-content-comparer

Not affiliated in any way, just a happy user.

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#12

Post by crecker » Sat, Aug 06, 2022, 1:41 PM UTC

dloss wrote: post #11

i-net PDFC is my favorite tool in this space (after having tried a dozen others). Awesome features, multi-platform. Free trial version and an online demo available. https://www.inetsoftware.de/products/pdf-content-comparer Not affiliated in any way, just a happy user.

Thanks for the comment! I think it's not too difficult to build something similar (even with a web server so you can make comparison on fly).

I'm playing with alpha compositing, I'm going to commit some little changes to enchant the experience a little bit.

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#13

Post by dloss » Sat, Aug 06, 2022, 1:43 PM UTC

dloss wrote: post #11

i-net PDFC is my favorite tool in this space (after having tried a dozen others). Awesome features, multi-platform. Free trial version and an online demo available. https://www.inetsoftware.de/products/pdf-content-comparer Not affiliated in any way, just a happy user.

And none of the other tools I've tried was significantly better than the old GPL-licensed version of DiffPDF: http://www.qtrac.eu/diffpdf-foss.html

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#14

Post by bob1029 » Sat, Aug 06, 2022, 1:46 PM UTC

rcfox wrote: post #4

I made a PDF diff tool for myself for one of my internships >10 years ago. One of my responsibilities was to get sign-off on any changes engineers made to schematics. (It was a really bad internship! I ended up automating a bunch of stuff for them because my actual job was mind-numbingly boring.) After the first few times comparing PDFs of schematics by eye, I said screw it and wrote a tool to export to PNGs and then…

Rasterization prior to comparison is a really clever idea. Doing this with PDF spec code would be an absolute nightmare. Checking 2 bitmaps for equality is just a few lines of code.

Many times, you aren't really concerned with the specific differences being described natively. You just want to know if a human would perceive differences between 2 copies of the "same" form.

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#15

Post by dloss » Sat, Aug 06, 2022, 1:54 PM UTC

crecker wrote: post #12

dloss wrote: post #11

i-net PDFC is my favorite tool in this space (after having tried a dozen others). Awesome features, multi-platform. Free trial version and an online demo available. https://www.inetsoftware.de/products/pdf-content-comparer Not affiliated in any way, just a happy user.

Thanks for the comment! I think it's not too difficult to build something similar (even with a web server so you can make comparison on fly). I'm playing with alpha compositing, I'm going to commit some little changes to enchant the experience a little bit.

Most important for me is the ability to ignore page boundaries. Removing the first half of the first page of one source document shouldn't produce differences on all following pages.

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#16

Post by crecker » Sat, Aug 06, 2022, 2:00 PM UTC

dloss wrote: post #15

crecker wrote: post #12

Earlier quoted context omitted.

Thanks for the comment! I think it's not too difficult to build something similar (even with a web server so you can make comparison on fly). I'm playing with alpha compositing, I'm going to commit some little changes to enchant the experience a little bit.

Most important for me is the ability to ignore page boundaries. Removing the first half of the first page of one source document shouldn't produce differences on all following pages.

Thanks for the feedback. Should the user specify the page boundaries or does pdf-diff automatically checks where page boundaries are?

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#17

Post by btown » Sat, Aug 06, 2022, 2:41 PM UTC

https://draftable.com is my go-to tool in this space. It understands text flow and the difference between structural and formatting differences, and is amazing when given PDFs of legal docs that you need to retroactively get a redline for. Incredible tool, free but not open source.

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#18

Post by svat » Sat, Aug 06, 2022, 2:46 PM UTC

See also diff-pdf https://vslavik.github.io/diff-pdf/ that I usually use for this. (Seems to be relatively popular; 1.4k stars on GitHub: https://github.com/vslavik/diff-pdf)

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#19

Post by crecker » Sat, Aug 06, 2022, 2:51 PM UTC

svat wrote: post #18

See also diff-pdf https://vslavik.github.io/diff-pdf/ that I usually use for this. (Seems to be relatively popular; 1.4k stars on GitHub: https://github.com/vslavik/diff-pdf )

I took inspiration from that repository too! :)

Re: Show HN: PDF-Diff - Visualize any differences between two PDFs

#20

Post by kondyt » Sat, Aug 06, 2022, 4:30 PM UTC

smartmic wrote: post #10

On Windows I was quite happy with DiffPDF[1]. As far as I remember there used to be an older open source version as well. But I could not found it on first glance. [1] https://www.qtrac.eu/diffpdf.html

That would be http://www.qtrac.eu/diffpdf-foss.html

There is a fork here: https://gitlab.com/eang/diffpdf