I know this question has been asked probably like a gazillion times, but here we go again.
I teach students using a digital jam board and to provide them with the pdf of the class I just export it. Now here comes the problem, the pdfs are always over 100 mbs which makes archiving them for the future very resource extensive. Now I stumbled upon djvu format and through their site I converted the pdf with coloured scanned 300 dpi setting. Now it took a lot of time for the document to get uploaded from my system directly so I used file sharing service and provided the link to the any2djvu site. Now I kid you not, a 103 mb pdf got converted into 1.73 mb djvu with rastor text and very good quality, which surprised me a lot. So I tried it with a couple of different pdfs and though the ratio was not like 100:2 but it was still phenomenal. So I not want to convert all of my class pdfs into djvu format, which is rather very time consuming to do manually through the website.
I tried looking at different forums and reddit threads and such but all the gui software always gave an error when converting the document and I don't know why, many gui softwares just straight up stopped after 20 or so pages. And as far as I could search I wasn't able to find a user friendly guide on setting up of the djvu for command line.
Now I am in no way a very tech savvy person but I am able to do basic command line conversions like converting images using imagemagick, downloading videos from youtube, c++, java, python. So if someone would be so kind as to give me a step by step guide for converting the pdfs just like how they get converted by the site when I select the setting of colored scanned document 300 dpi, and also help me automate the complete process.
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If I was you, I'd 1st find out why your pdfs are so huge. In case I'm getting you right the pdfs are produced by you.
1. quickly convert a pdf to html+stuff. Use pdftohtml from poppler.
2. See what parts are enormous.
As for the conversion, it's basically two-stage:
1. pdf to a set of pictures (see pdftoppm)
2. pictures to djvu with djvu-utils
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi. In my experience, the largest PDF I could upload to any2djvu was about 30 MB. Above that, the conversion was still running more than 1 hour later. Have you tried to upload your PDF to pdf2djvu.com? I have not tried sending a big PDF to that site, just a suggestion.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
I know this question has been asked probably like a gazillion times, but here we go again.
I teach students using a digital jam board and to provide them with the pdf of the class I just export it. Now here comes the problem, the pdfs are always over 100 mbs which makes archiving them for the future very resource extensive. Now I stumbled upon djvu format and through their site I converted the pdf with coloured scanned 300 dpi setting. Now it took a lot of time for the document to get uploaded from my system directly so I used file sharing service and provided the link to the any2djvu site. Now I kid you not, a 103 mb pdf got converted into 1.73 mb djvu with rastor text and very good quality, which surprised me a lot. So I tried it with a couple of different pdfs and though the ratio was not like 100:2 but it was still phenomenal. So I not want to convert all of my class pdfs into djvu format, which is rather very time consuming to do manually through the website.
I tried looking at different forums and reddit threads and such but all the gui software always gave an error when converting the document and I don't know why, many gui softwares just straight up stopped after 20 or so pages. And as far as I could search I wasn't able to find a user friendly guide on setting up of the djvu for command line.
Now I am in no way a very tech savvy person but I am able to do basic command line conversions like converting images using imagemagick, downloading videos from youtube, c++, java, python. So if someone would be so kind as to give me a step by step guide for converting the pdfs just like how they get converted by the site when I select the setting of colored scanned document 300 dpi, and also help me automate the complete process.
If I was you, I'd 1st find out why your pdfs are so huge. In case I'm getting you right the pdfs are produced by you.
1. quickly convert a pdf to html+stuff. Use pdftohtml from
poppler.2. See what parts are enormous.
As for the conversion, it's basically two-stage:
1. pdf to a set of pictures (see pdftoppm)
2. pictures to djvu with djvu-utils
Try https://github.com/FriedrichFroebel/pdf2djvu
(no dot at the end!)
Last edit: Janusz 2023-09-05
Thanks, will give it a try and ask if I encounter any problems.
Last edit: Partham 2023-09-05
Last edit: Ildar Mulyukov 2023-09-08
Hi. In my experience, the largest PDF I could upload to any2djvu was about 30 MB. Above that, the conversion was still running more than 1 hour later. Have you tried to upload your PDF to pdf2djvu.com? I have not tried sending a big PDF to that site, just a suggestion.