Batch Resize

All it takes is one line to resize a directory full of images to your desired size if you have the ImageMagick tools package installed. convert is a tool that comes with that package.

To install ImageMagick: (on Debian/Ubuntu based systems)

sudo apt-get install imagemagick

To resize only:

find . -iname '*.jpg' -exec convert {} -resize 640x480 {} \;

To resize and convert to another format (example converts JPEG to PNG):

find . -iname '*.jpg' -exec convert {} -resize 640x480 {}.png \;