script.sh

#!/bin/bash
# Convert jpg files into pngs

for img in *.jpg
  do 
    convert "$img" "$img.png";
    rm "$img";
  done

# renaming files from .jpn.png to .png
rename 's/\.jpg\.png/\.png/' *.png

# removing extra spaces
rename 's/ //' *.png

# toLowerCase
rename 'y/A-Z/a-z/' *