Add Random Background after Removal

#!/bin/bash

for f in *.png; do
    background=$(ls -1 ../backgrounds/*.jpg | shuf -n 1)
    convert "$background" -resize "$(identify -format "%wx%h" "$f")^" -gravity center -extent $(identify -format "%wx%h" "$f") temp_background.jpg
    convert temp_background.jpg "$f" -composite "output_$f"
    rm temp_background.jpg
done

Transparent foreground and Background image arrangement:
parent_directory/
    ├── foreground_images_folder/
    │   ├── image1.png
    │   ├── image2.png
    │   └── script.sh
    └── backgrounds/
        ├── background1.jpg
        ├── background2.jpg
        └── ...