Image optimization bash script

Prerequisite

• jpegoptim for jpg optimization
• optipng for png optimization
• cwebp for WebP conversion
• go-avif for Avif conversion

From APT repositories

Debian/Ubuntu :

sudo apt install jpegoptim optipng webp -y

Centos 7 :

sudo yum install optipng jpegoptim libwebp-tools -y

Compile the latest release (optipng & libwebp)

For Debian/Ubuntu (available in scripts folder) :

# optipng
curl -sL git.io/fjddn | sudo -E bash

# libwebp
curl -sL git.io/fjdd6 | sudo -E bash

Go-Avif installation

sudo wget -qO /usr/local/bin/avif https://github.com/Kagami/go-avif/releases/download/v0.1.0/avif-linux-x64
sudo chmod +x /usr/local/bin/avif

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Installation

1. Clone the repository

git clone https://github.com/VirtuBox/img-optimize.git $HOME/.img-optimize

2. Install the script

Method 1 : Add an alias in .bashrc

With this method img-optimize can only be used by the current user

echo "alias img-optimize=$HOME/.img-optimize/optimize.sh" >> $HOME/.bashrc
source $HOME/.bashrc

Method 2 : Add an alias to the script in /usr/local/bin

With this method img-optimize can be used by all users

sudo ln -s $HOME/.img-optimize/optimize.sh /usr/local/bin/img-optimize
sudo chmod +x /usr/local/bin/img-optimize

Usage

Bash script to optimize your images and convert them in WebP
Usage: img-optimize [options] <images path>
If images path isn't defined, img-optimize will use the current directory
  Options:
       --jpg ..... optimize all jpg images
       --png ..... optimize all png images
       --webp ..... convert all images in webp
       --avif ..... convert all images in avif
       --std ..... optimize all png & jpg images
       --next ..... convert all images in webp & avif
       --all ..... optimize all images (png + jpg + webp + avif)
       -i, --interactive ..... run img-optimize in interactive mode
       -q, --quiet ..... run image optimization quietly
       --path <images path> ..... define images path
 Other options :
       -h, --help, help ... displays this help information
       --cmin [+|-]<n> ... File's status was last changed n minutes ago.
         act find cmin argument (+n : greater than n, -n : less than n, n : exactly n)
Examples:
  optimize all jpg images in /var/www/images
    img-optimize --jpg --path /var/www/images

Update the script

To update the script, just run :

git -C $HOME/.img-optimize pull

Setup daily cronjob

You just have to copy the scripts to /etc/cron.daily :

cp $HOME/.img-optimize/crons/jpg-png-cron.sh /etc/cron.daily/jpg-png-cron
cp $HOME/.img-optimize/crons/jpg-png-cron.sh /etc/cron.daily/webp-cron

chmod +x /etc/cron.daily/jpg-png-cron
chmod +x /etc/cron.daily/webp-cron

Then just edit your websites path set with the variables sites at the beginning of the cron scripts.

Warning

Conversion process can take a while, you can use tmux to launch the script and be able to close your ssh connection without interrupting conversion. Then just use tmux attach to login back in your tmux session.

Credits

• WebP conversion script was inspired by this DigitalOcean Community Tutorial

• Tutorial about webp conversion available on jesuisadmin.fr (in french)