How to resize pictures in Knoppix command-line

Here's a short how-to to reduce the size of picture files downloaded from a digicam, to prepare the picture files for upload to Facebook or other social network sites.

One word: Mogrify.

sudo apt-get install imagemagick

after the package installs, go to the folder containing the images you want resized, and go ahead to resize all the pictures to your preferred size, mine being 800x600. You also have to watch the lower - upper case of the file extension for the jpeg files, it could be ALL CAPS or small caps.

mogrify -resize 800x600 *.JPG

Here is a more detailed reference.