Guetzli is a Google program to optimize JPEG images. Unfortunately, it only works one file at a time. With this script in Python you can do it recursively a whole folder.
Image Author: Senjuti Kundu
Guetzli must be installed on your system. Follow the official instructions. Guetzli
and 2.7.10 or Python 3.
After
pip3 install guetzli-recursively
guetzli_recursively [folder]
guetzli_recursively img/
out
img/tasks.jpg
Save 6%
img/portfolio/idecrea/space.jpg
It is not necessary to optimize
img/portfolio/home.jpg
Save 3%
Must be greater than or equal to 84.
guetzli_recursively --quality 85 img/
guetzli_recursively --memlimit 28000 img/