Image Quality Reduction and Watermark with imagemagick

res-reduction-plus-watermark.sh

# move to a main image folder
sudo apt-get install imagemagick
# create a redux folder
mkdir ./redux
for f in *.jpg; do   convert $f -quality 80 ./redux/$f;done
# move into redux
cd ./redux
#create watermarked folder
mkdir ./watermarked
#i use a logo.png file placed in main image folder
for f in *.jpg; do   composite -gravity south -dissolve 30 -gravity center -geometry +0+20 ./../logo.png $f ./watermarked/$f;done