Automatically adding a number to each image in a directory

I want to display a number on top of each image, for all image files in a directory. In other words, each image is modified to contain a box containing a number. How can I automate this?

This bash-script does that. It uses imagemagick. Install imagemagick by apt-get install imagemagick on Ubuntu and Debian systems, and a similar yum command on Fedora. The trick is to increase a counter for each image, and use that value when writing the label on each image. All commands used by the script have existed in Ubuntu/Debian since at least 2016, and works with Ubuntu 21.10 as well.

#!/bin/bash
mkdir -p out #creates an output directory called 'out'
i=0
ls -1 *.jpg *.JPEG *.jpeg *.JPG 2>/dev/null|while read image
do
  number=$(printf "%02d" $i)
  convert "$image" -fill black -undercolor '#FFFFFF' -pointsize 25 -gravity northwest -annotate +10+10 "$number" "out/$image"
  ((i=i+1))
done