https://github.com/sindresorhus/gulp-imagemin
https://github.com/imagemin/imagemin
origin - http://www.pipiscrew.com/?p=7003 minify-images-with-node
https://github.com/sindresorhus/gulp-imagemin
https://github.com/imagemin/imagemin
origin - http://www.pipiscrew.com/?p=7003 minify-images-with-node