resizing a number of images using the convert command line tool

Problem: I have a directory full of images and I want to get thumbnails out of the process. I tried used the 'convert -size' command but that doesn't seem to do the trick.

Answer: By making use of the convert -size and then the resize it's possible to achieve the desired result.

for file in `ls *.jpg`; do convert -size FooxBar $file -resize Num1xNum2 output/small_${file}; done