Automating Image Optimization on Linux

If your Linux server is getting bogged down by large image files, you can automate the process of resizing and compressing them using a simple Bash script. This guide will help you set up an automated image optimization process.

Installing Required Tools

You'll need ImageMagick, jpegoptim, and pngquant for resizing and optimizing images.

sudo dnf install epel-release -y
sudo dnf install imagemagick jpegoptim pngquant -y

The Optimization Script

Create a script called shrink_images.sh and paste the following:

#!/bin/bash

# Set the target size limit (1.5MB = 1536k)
SIZE_LIMIT="+1536k"

# Find and process JPEG and PNG images
find /var/www -type f \( -iname "*.jpg" -o -iname "*.jpeg" -o -iname "*.png" \) -size $SIZE_LIMIT | while read file; do
    echo "Processing: $file"

    # Resize images larger than 1920px while keeping aspect ratio
    convert "$file" -resize '1920x1920>' "$file"

    # Optimize JPEG files
    if [[ $file == *.jpg || $file == *.jpeg ]]; then
        jpegoptim --strip-all --max=80 "$file"
    fi

    # Optimize PNG files
    if [[ $file == *.png ]]; then
        pngquant --force --ext .png --quality=65-80 "$file"
    fi
done

echo "Image optimization completed!"

Making the Script Executable

After saving the script, give it execution permissions:

chmod +x shrink_images.sh

Running the Script

To manually optimize images, run:

./shrink_images.sh

Automating with a Cron Job

To automate the process, schedule it with cron:

crontab -e

Add this line to run the script every night at midnight:

0 0 * * * /path/to/shrink_images.sh >> /var/log/shrink_images.log 2>&1

Verifying Optimization

To check disk space before and after optimization, use:

du -sh /var/www

Conclusion

With this script, you can automatically resize and compress large images, improving your server performance and saving disk space.

Happy optimizing!