Magento Image Optimisation

The Problem

One of our clients recently needed a simple solution for automatically optimising their media/ and skin/ images. After trying a reputable module we decided it would be simpler and give us more control if we completed this using bash, cron, jpegoptim and optipng.

The Solution

Usage

• Set the path to your media/ and skin/ directories. This is relative to the scripts location.
• Install jpegoptim and optipng. These will likely be available in your package manager if you use Linux.
• Backup your current media/ and skin/ directories.
• Set arguments for jpegoptim and optipng in the optimiseJpeg() and optimisePng() functions respectively. In the end we were able to get the results we needed using only lossless compression. This is what the script is currently configured for.
• Make a first pass through all the images so that existing images are compressed. This can be done by running the script with a large period. I used 5256000 for a period of 10 years.

bash img_optimiser.bash 5256000 &>> img_optimiser.log

• Setup cron to run the script regularly and optimise any new images as they’re added. You’ll need to set the period (in minutes) to match the period of your cron job. I’m running the script every hour with a period of 60.

0 * * * * bash /path/to/img_optimiser.bash 60 2>&1 >> /path/to/img_optimiser.log

The 2>&1 allows you to log stdout and stderr into one file from cron.