JPG and PNG image bulk optimization
Install jpegoptim and optipng
apt update && apt install jpegoptim optipng -y
JPG optimization
cd /path/to/your/image/folder
find . -iname "*.jp*" -print0 | xargs -0 jpegoptim --strip-all -m76
PNG optimization
cd /path/to/your/image/folder
find . -iname '*.png' -print0 | xargs -0 optipng -o7 -preserve