Install leafo/magick

Install ImageMagick's MagicWand or GraphicsMagick's Wand

$ sudo apt-get install luajit

$ sudo apt-get install libmagickwand-dev

$ sudo apt-get install libgraphicsmagick1-dev

$ sudo apt-get install luarocks
$ luarocks install magick

extra tools

sudo apt-get update
sudo apt-get install imagemagick

http://www.charry.org/docs/linux/ImageMagick/ImageMagick.html

mogrify -sample 200x200 *.jpg

convert -resize 100x100 foo.jpg thumbnail.jpg