Show HN: PDF-Diff - Visualize any differences between two PDFs
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Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#2Did you try it with more complicated PDFs?
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#3Did you try it with more complicated PDFs?
Thanks for your comment! By complicated PDFs, what do you mean exactly? A lot of pages? With forms? I've tried with standard technical books I have bought.
The pdf-diff tool simply captures a sort of "screenshot" of a PDF page and then compares it against to the page from the second PDF file you'd like to compare. Since it works by comparing raw pixels, I guess it'll work with complicated PDFs.
Now "working" does not mean it's a good result for the eye and this is why I asked for help regarding some issues.
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#4I 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 compare them pixel-by-pixel. It saved me a ton of time and my sanity.
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#5I 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…
> 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 compare them pixel-by-pixel. It saved me a ton of time and my sanity.
It saved mine! I usually work with books and sometimes it's really difficult to tell 10 people to check every single page if something has been different to a previous pdf I sent. They will never be able to find all the differences because we're humans, not bot. We make mistakes.
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#6Did you try it with more complicated PDFs?
Thanks for your comment! By complicated PDFs, what do you mean exactly? A lot of pages? With forms? I've tried with standard technical books I have bought. The pdf-diff tool simply captures a sort of "screenshot" of a PDF page and then compares it against to the page from the second PDF file you'd like to compare. Since it works by comparing raw pixels, I guess it'll work with complicated PDFs. Now "working" does not…
Aha. If one paragraph is added on page 1, it might show a diff on every following page in the same chapter after that, if it causes things to shift?
It's not easy to decide when such a change needs review and when it doesn't
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#7Earlier quoted context omitted.
Thanks for your comment! By complicated PDFs, what do you mean exactly? A lot of pages? With forms? I've tried with standard technical books I have bought. The pdf-diff tool simply captures a sort of "screenshot" of a PDF page and then compares it against to the page from the second PDF file you'd like to compare. Since it works by comparing raw pixels, I guess it'll work with complicated PDFs. Now "working" does not…
Aha. If one paragraph is added on page 1, it might show a diff on every following page in the same chapter after that, if it causes things to shift? It's not easy to decide when such a change needs review and when it doesn't
Yes, if it causes things to shift, the tool shows every page red. This tool is meant to be ran in the final phase of typesetting, the moment when you want to focus attention on details (e.g. spacing).
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#8Did you try it with more complicated PDFs?
Thanks for your comment! By complicated PDFs, what do you mean exactly? A lot of pages? With forms? I've tried with standard technical books I have bought. The pdf-diff tool simply captures a sort of "screenshot" of a PDF page and then compares it against to the page from the second PDF file you'd like to compare. Since it works by comparing raw pixels, I guess it'll work with complicated PDFs. Now "working" does not…
ImageMagick's `compare` can do this as well, on a pixel-level.
The issue is that in some cases, for example when the change is that a long sentence has been inserted in the middle of the document, the following headline and some of the first paragraph of the following section move to the next page. Then everything that follows is just marked red and the diff becomes useless.
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#9Earlier quoted context omitted.
Thanks for your comment! By complicated PDFs, what do you mean exactly? A lot of pages? With forms? I've tried with standard technical books I have bought. The pdf-diff tool simply captures a sort of "screenshot" of a PDF page and then compares it against to the page from the second PDF file you'd like to compare. Since it works by comparing raw pixels, I guess it'll work with complicated PDFs. Now "working" does not…
ImageMagick's `compare` can do this as well, on a pixel-level. The issue is that in some cases, for example when the change is that a long sentence has been inserted in the middle of the document, the following headline and some of the first paragraph of the following section move to the next page. Then everything that follows is just marked red and the diff becomes useless.
> ImageMagick's `compare` can do this as well, on a pixel-level.
Yes, thanks for the comment. I wanted to build something with golang :)
Re: Show HN: PDF-Diff - Visualize any differences between two PDFs
#10On 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.