Compresspdf.sh
Script
#! /bin/bash
pdffile=$1;
dpi=$2
gs \
-o "${pdffile%.pdf}-resampled.pdf" \
-sDEVICE=pdfwrite \
-dDownsampleColorImages=true \
-dDownsampleGrayImages=true \
-dDownsampleMonoImages=true \
-dColorImageResolution=$dpi \
-dGrayImageResolution=$dpi \
-dMonoImageResolution=$dpi \
-dColorImageDownsampleThreshold=1.0 \
-dGrayImageDownsampleThreshold=1.0 \
-dMonoImageDownsampleThreshold=1.0 \
"${pdffile}"
How to work with it?
What does this script do?
This script squashes large PDFs into very small ones.
In which context was it made?
The script is written by Open Source Publishing. It has since travelled through other practices to be used for a variety of applications, usually at the eleventh hour before sending PDFs to print and for grant applications.
What software does it use?
ghostscript
How to download these pieces of software?
Go to the URL https://www.ghostscript.com/, you can download it from there.
On which systems can this script run?
This works on Linux systems, also on Mac OS. Windows works differently, and it is likely it won't work there.
How to run the script?
After installing the software ghostscript (see above), save the code above as a bash script with the .sh extension, for example: compresspdf.sh. Don't forget to add #! /bin/bash to the top of your script!
Then, in a terminal session, navigate to the directory where you have the file saved. You should add the PDF you want to compress to the same directory.
Then do:
./compresspdf.sh <file.pdf> <resolution in DPI>
For example:
./compresspdf.sh input.pdf 300
The output will be something like:
input-resampled.pdf
Compressing the PDF for the newspaper Toward A Minor Tech
This script has been used many times on many machines. It's super handy when making files that need to be sent over a network. One particular use was when making the final final final PDF to be sent to the printer for the newspaper Toward A Minor Tech in January 2023 at Varia.
The newspaper was created during a book sprint, where writers and editors worked in London, while the designers worked in Rotterdam. High-resolution images were uploaded to this very wiki so that they would appear crisp and non-pixelated in the printed newspaper.
BUT! At the eleventh hour, we found the PDF to be quite large. We needed to send this on to the printer Drukkerij Tripiti in Rotterdam, and email was our preferred option. Of course, a USB flash drive could be hand-delivered, but this was not the fastest way. Also it would be a bit weird, in 2023 who delivers files by hand? And there is no signage on the door at Drukkerij Tripiti, nor indication of what their business hours are.
So, we used this script. We managed to get the file down to a manageable size without stress.