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What are fast and reliable ways for converting a PDF into a (single) JPEG using the command line on Linux?

Matthias Braun
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Soerendip
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  • If you build xpdf from sources it comes with little utilities for things like pdftotext, pdftojpeg, and podftohtml. They might be distributed with some Linux distros but they don't seem to be in this Debian I'm using. – Alan Corey Nov 29 '20 at 16:24
  • Sorry, they're in poppler-utils. pdfdetach, pdffonts, pdfimages, pdfinfo, pdfseparate, pdfsig, pdftocairo, pdftohtml, pdftoppm, pdftops, pdftotext and pdfunite. Or build xpdf from sources, I'm pretty sure. – Alan Corey Nov 29 '20 at 18:40
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    Voting to reopen. I don't see this as a question about "general computing hardware and software", I see it as a question about bash CLI programming. – Gabriel Staples Jan 19 '22 at 05:32
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    What @GabrielStaples says. I came here precisely to find this out, and I don't know of another place to look for this answer. – Mike Maxwell Jun 16 '23 at 15:43

4 Answers4

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For the life of me, over the last 5 years, I cannot get imagemagick to work consistently (if at all) for me, and I don't know why people continually recommend it again and again. I just googled how to convert a PDF to a JPEG today, found this answer, and tried convert, and it doesn't work at all for me:

Broken command (doesn't work for me):

# BROKEN cmd
$ convert in.pdf out.jpg
convert-im6.q16: not authorized `in.pdf' @ error/constitute.c/ReadImage/412.
convert-im6.q16: no images defined `out.jpg' @ error/convert.c/ConvertImageCommand/3258.

(Update 24 Feb. 2022: here is the fix for imagemagick so convert will work. See also my comment here, and my comments under this answer here. I still like pdftoppm, below, much better, however.)

Then, I remembered there was another tool I use and wrote about, so I googled "linux convert pdf to jpg Gabriel Staples", clicked the first hit, and scrolled down to my answer. Here's what works perfectly for me. This is the basic command format:

Good command--use this instead:

# GOOD cmd
pdftoppm -jpeg -r 300 input.pdf output

Note: on Linux Ubuntu, you may need to do sudo apt update && sudo apt install poppler-utils in order to install pdftoppm. Thanks, @Reynadan.

The -jpeg sets the output image format to JPG, -r 300 sets the output image resolution to 300 DPI, and the word output will be the prefix to all pages of images, which will be numbered and placed into your current directory you are working in. A better way, in my opinion, however, is to use mkdir -p images first to create an "images" directory, then set the output to images/pg so that all output images will be placed cleanly into the images dir you just created, with the file prefix pg in front of each of their numbers.

Therefore, here are my favorite commands:

  1. [Produces ~1MB-sized files per pg] Output in .jpg format at 300 DPI:

    mkdir -p images && pdftoppm -jpeg -r 300 mypdf.pdf images/pg

  2. [Produces ~2MB-sized files per pg] Output in .jpg format at highest quality (least compression) and still at 300 DPI:

    mkdir -p images && pdftoppm -jpeg -jpegopt quality=100 -r 300 mypdf.pdf images/pg

  3. If you need more resolution, you can try 600 DPI:

    mkdir -p images && pdftoppm -jpeg -r 600 mypdf.pdf images/pg

  4. ...or 1200 DPI:

    mkdir -p images && pdftoppm -jpeg -r 1200 mypdf.pdf images/pg

See the references below for more details and options.

References:

  1. [my answer] Convert PDF to image with high resolution
  2. [my answer] https://askubuntu.com/questions/150100/extracting-embedded-images-from-a-pdf/1187844#1187844

Keywords: ubuntu linux convert pdf to images; pdf to jpeg; ptdf to tiff; pdf2images; pdf2tiff; pdftoppm; pdftoimages; pdftotiff; pdftopng; pdf2png

Benjamin Loison
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Gabriel Staples
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  • For creating a single file do: `pdftoppm -singlefile -jpeg -r 300 input.pdf output`. I also share the frustration btw :). Maybe you can edit your answer to include this short version as well. Creating the dir might put people off. – Steve Chavez Jun 12 '20 at 04:19
  • @SteveChavez, I just updated my answer to show a shorter version too, and to explain what I'm doing with the `mkdir -p images` part of the command. Thanks. – Gabriel Staples Dec 07 '20 at 17:27
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    @SteveChavez -singlefile, per the documentation, will "write only the first page and do not add digits". That means if your intent is to generate one long image of all the pages stacked vertically (or stitched horizontally), this will not work. – brianjcohen Aug 03 '21 at 14:28
  • @SteveChavez, I just confirmed what @brianjcohen said. Using `-singlefile` caused `pdftoppm` to only convert the first page of a 46 pg PDF I just tested it on. – Gabriel Staples Aug 03 '21 at 19:22
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    imagemagick did not work for me on Ubuntu 20.04. this worked like a charm! – MIkee Oct 31 '21 at 13:08
  • Can you just please remove the command that _doesn't work_ so that future people who read quickly will not needlessly try it first? :-)) it doesn't add any value does it – matanster Jan 26 '22 at 11:51
  • @matanster, I'd like to keep the broken command, because I do think it adds value, so I added some bold headings to make it super clear which command is broken and which one works. The value I think keeping the broken command adds is: 1) it makes that error string googlable so when others see that command is broken and they search for solutions, they can find this answer and see the alternative command option, 2) it reminds me I've seen this error before (I reference this answer all the time myself too), 3) it gives someone a chance who sees this to offer a fix for the `convert` command. – Gabriel Staples Jan 26 '22 at 16:38
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    @matanster, also, keep in mind I wrote my answer 3 years after [the other answer](https://stackoverflow.com/a/43085991/4561887), which uses that `convert` command I find to be broken, was accepted as correct. I felt I needed to provide justification for why I'd add a new answer to a 3-yr-old question which already has an accepted and highly-upvoted answer. Only in the last month or so has my answer finally surpassed the original answer in votes. – Gabriel Staples Jan 26 '22 at 16:41
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    `pdftoppm` did the trick for me. `convert` worked too, but the resulting jpeg was extremely blurry. With `pdftoppm` the result was way better. So I'd recommend it even if you don't have the problem of `convert` not working. – Andyc Apr 10 '22 at 19:15
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    you need to do `sudo apt install poppler-utils` to use pdftoppm command – Reynadan Apr 05 '23 at 15:03
  • Damn, what's wrong with `convert` nowadays? – Ricky Robinson Aug 22 '23 at 13:06
  • @RickyRobinson, see in my answer: "here is the fix for imagemagick so `convert` will work". It's been broken for years--at least 3 or 4. – Gabriel Staples Aug 22 '23 at 14:06
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You can try ImageMagick's convert utility.

On Ubuntu, you can install it with this command:

$ sudo apt-get install imagemagick

Use convert like this:

$ convert input.pdf output.jpg
# For good quality use these parameters
$ convert -density 300 -quality 100 in.pdf out.jpg
Matthias Braun
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janfitz
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    If you get an error like `convert: not authorized 'filename.pdf' @ error/constitute.c/ReadImage/412.`, then you need to modify `/etc/ImageMagick-6/policy.xml` or just temporarily rename it. – mivk Sep 17 '19 at 15:04
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    Unfortunately this doesn't work for me. See the `pdftoppm` answer for a more effective solution. – Steve Chavez Jun 12 '20 at 04:09
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    I needed this to get a high-quality JGP instead of a low resolution one: `convert -density 300 -quality 100 in.pdf out.jpg` – Matthias Braun Jun 17 '20 at 17:30
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    @mivk what modifications are needed in `policy.xml` ? – A.W. Aug 31 '20 at 20:30
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    @Guus : In my policy.xml, I need to comment out the line ``. But I usually prefer just temporarily renaming the file when I come across this error. – mivk Sep 01 '20 at 10:41
  • @mivk Seriously that file is a pain in my side I wish by default there were no such limitations that necessitated me having to dig around to figure out why it won't do what I ask so often – Michael Apr 18 '21 at 19:24
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    what kind of monstrosity is that? Why is there a "policy" in the first place? What are these stupid rules protecting against? – 400 the Cat Aug 19 '21 at 08:52
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    Imagemagic doesn't work on many distros and making it work on Linux causes security issues. Please stop recommending it. – Masoud Oct 06 '21 at 18:09
  • don't use the -flatten, and -trim options on multipage printable pdf conversion -flatten - puts all pages over on a single image -trim - cuts the white margin up to the text – Aak Apr 03 '23 at 20:41
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libvips can convert PDF -> JPEG quickly. It comes with most linux distributions, it's in homebrew on macos, and you can download a windows binary from the libvips site.

This will render the PDF to a JPG at the default DPI (72):

vips copy somefile.pdf somefile.jpg

You can use the dpi option to set some other rendering resolution, eg.:

vips copy somefile.pdf[dpi=600] somefile.jpg

You can pick out pages like this:

vips copy somefile.pdf[dpi=600,page=12] somefile.jpg

Or render five pages starting from page three like this:

vips copy somefile.pdf[dpi=600,page=3,n=5] somefile.jpg

The docs for pdfload have all the options.

With this benchmark image, I see:

$ /usr/bin/time -f %M:%e convert -density 300 r8.pdf[3] x.jpg
276220:2.17
$ /usr/bin/time -f %M:%e pdftoppm -jpeg -r 300 -f 3 -l 3 r8.pdf x.jpg
91160:1.24
$ /usr/bin/time -f %M:%e vips copy r8.pdf[page=3,dpi=300] x.jpg
149572:0.53

So libvips is about 4x faster and needs half the memory, on this test at least.

jcupitt
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Convert from imagemagick seems to do a good job:

convert file.pdf test.jpg

and in case there were multiple files generated:

convert test-0.jpg -append test-1.jpg ... -append one.jpg

to generate a single file, where all pages are concatenated.

Martin
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Soerendip
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