mirror of https://gitlab.com/curben/blog
86 lines
2.4 KiB
Markdown
86 lines
2.4 KiB
Markdown
---
|
|
title: Make PDF files smaller
|
|
date: 2019-01-05 00:00:00
|
|
tags:
|
|
---
|
|
|
|
The most effective ways of reducing the file size of a PDF is by converting to grayscale and reduce the resolution.
|
|
|
|
<!-- more -->
|
|
|
|
Requirement: ghostscript (installed by default in Ubuntu)
|
|
|
|
## Single PDF
|
|
|
|
Save the following script as "pdfcompress.sh".
|
|
|
|
Usage: `sh pdfcompress.sh input.pdf`
|
|
|
|
The output compressed file is named as "input.compressed.pdf"
|
|
|
|
```bash
|
|
#!/bin/sh
|
|
|
|
filename=$(basename "$1")
|
|
dir=$(dirname "$1")
|
|
|
|
gs \
|
|
-sOutputFile="$dir/${filename%.*}.compressed.pdf" \
|
|
-sDEVICE=pdfwrite \
|
|
-dPDFSETTINGS=/ebook \
|
|
-sColorConversionStrategy=Gray \
|
|
-sColorConversionStrategyForImages=/Gray \
|
|
-dProcessColorModel=/DeviceGray \
|
|
-dCompatibilityLevel=1.4 \
|
|
-dNOPAUSE -dBATCH -dQUIET \
|
|
"$1"
|
|
```
|
|
|
|
|
|
Options ([more info](https://ghostscript.com/doc/current/Ps2pdf.htm#Options)):
|
|
|
|
- Remove **ColorConversionStrategy**, **ColorConversionStrategyForImages** and **ProcessColorModel** lines to retain colour.
|
|
- **PDFSETTINGS**:
|
|
- */default* selects output intended to be useful across a wide variety of uses. 72 DPI.
|
|
- */screen* selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting. 72 DPI.
|
|
- */ebook* selects medium-resolution output similar to the Acrobat Distiller "eBook" setting. 150 DPI.
|
|
- */printer* selects output similar to the Acrobat Distiller "Print Optimized" setting. 300 DPI.
|
|
- */prepress* selects output similar to Acrobat Distiller "Prepress Optimized" setting. 300 DPI.
|
|
|
|
## PDFs in a folder
|
|
|
|
Use the following script to compress all PDFs in a folder.
|
|
|
|
Usage: `sh pdfcompress.sh 'target folder'`
|
|
|
|
```bash
|
|
#!/bin/sh
|
|
|
|
cd "$1"
|
|
|
|
for i in *.pdf; do
|
|
[ -f "$i" ] || break
|
|
|
|
# Skip compressed PDFs
|
|
echo "$i" | grep --quiet ".compressed.pdf"
|
|
|
|
if [ $? = 1 ]
|
|
then
|
|
gs \
|
|
-sOutputFile="${i%.*}.compressed.pdf" \
|
|
-sDEVICE=pdfwrite \
|
|
-dPDFSETTINGS=/ebook \
|
|
-sColorConversionStrategy=Gray \
|
|
-sColorConversionStrategyForImages=/Gray \
|
|
-dProcessColorModel=/DeviceGray \
|
|
-dCompatibilityLevel=1.4 \
|
|
-dNOPAUSE -dBATCH -dQUIET \
|
|
"$i"
|
|
fi
|
|
done
|
|
```
|
|
|
|
<br/>
|
|
Source: [Internal Pointers](https://www.internalpointers.com/post/compress-pdf-file-ghostscript-linux), [firstdoit](https://gist.github.com/firstdoit/6390547), [ahmed-musallam](https://gist.github.com/ahmed-musallam/27de7d7c5ac68ecbd1ed65b6b48416f9), [Ghostscript Docs](https://ghostscript.com/doc/current/Ps2pdf.htm)
|
|
|