Hello, friends. The terminal is a great Linux tool. With it, we can do many things and if we install other programs we can extend its functionality even more. Want an example? Today, you will learn how to convert JPG images to PDF using the terminal.
ImageMagick to the rescue
According to the GitHub profile:
ImageMagick uses multiple threads to increase performance and can read, process or write mega, giga or tera-pixel sized images. The current version is the
ImageMagick 7.1.0 series. It runs on Linux, Windows, Mac OS X, iOS, Android OS and others.
ImageMagick is free software that is delivered as a ready-to-run binary distribution or as source code that you can use, copy, modify and distribute in both open and proprietary applications. It is distributed under an Apache 2.0 derivative license.
In short, ImageMagick is a software tool that you can use for image processing on your computer. Thanks to it, we can do many things with images. That is to say, edit them, manipulate them and so on.
Thanks to ImageMagick, we can convert JPG images to PDF so that we can quickly have them in a document.
Let’s get started.
Install ImageMagick on Linux
Fortunately, we can install ImageMagick on many Linux distributions because it is available from the official repositories of many of them.
sudo apt update sudo apt install imagemagick
Concerning Arch Linux, Manjaro, and derivatives
sudo pacman -S imagemagick
Then, we can continue.
How to convert JPG images to PDF using the terminal
The procedure is simple, just follow the following syntax
convert [jpg-file] [output-pdf]
convert 1.jpg o.pdf
You will get a PDF with the content of the image.
You can add several files at once
convert 1.jpg 2.jpg 3.jpg o.pdf
Remember that I’m working with relative paths, but you can also do it with absolute paths
convert /home/angelo/1.jpg o.pdf
And so on. You can add all the images in a folder.
convert *.jpg o.pdf
By default, ImageMagick uses the highest possible quality to convert images to PDF. But if there are many images, this can cause a problem. So, you can also specify the quality at which you want the images to be converted.
To achieve this, use the
--quality option and assign a number less than
100 which is the limit. For example:
convert --quality 75 1.jpg o.pdf
This is especially useful when you have many images or just want a backup.
Possible problem with ImageMagick
It is possible that when you execute the above commands, you get an error like this
convert-im6.q16: attempt to perform an operation not allowed by the security policy `PDF' @ error/constitute.c/IsCoderAuthorized/421.
This is due to a security issue with
Ghostscript. An alternative then is to disable the lock for PDF files.
Edit the configuration file
sudo nano /etc/ImageMagick-6/policy.xml
And edit the line
<policy domain="coder" rights="none" pattern="PDF" />
<!-- <policy domain="coder" rights="none" pattern="PDF" /> --> -->
So, all we are doing is adding a comment to ignore it.
Save the changes and close the editor. That’s enough.
Doing things through the terminal is not difficult, but it gives us another way of doing things. They are also very useful in scripting and so on.