Generate a slideshow of images for cover art trivia

slideshow.sh

#!/bin/bash

# Generate a slideshow of images for cover art trivia.
# Files should be named like {SORT-NUMBER} blah blah blah.jpg

for f in *.jpg; do 
  num=$(echo $f | sed -En "s/^([0-9]+).+?/\1/p")
  formatNum="$((10#$num + 1 - 1))"
  output=final_$num.jpg
  echo "Processing $f file...";
  convert -caption "Cover #$formatNum" $f -pointsize 48 -gravity center -background black +polaroid $output
done