imgoptim

#!/bin/bash
#
# sudo apt-get install jpegoptim
# sudo apt-get install optipng
#
IMGFOLDER=/path/to/image/folder
JPGLOG=/path/to/image/folder/jpegoptim.log
PNGLOG=/path/to/image/folder/pngoptim.log
JPGCOMPRESSION=75
echo `date` >> $PNGLOG
find $IMGFOLDER -mtime -2 -iname '*.png' -print0 | \
 xargs -0 optipng -o7 -log $PNGLOG -preserve
echo `date` >> $JPGLOG
find $IMGFOLDER -mtime -2 -iname '*.jpg' -print0 | \
 xargs -0 jpegoptim --max=$JPGCOMPRESSION --preserve --totals >> $JPGLOG