pdf2imgpdf.sh

#!/bin/bash

# Check all required CLIs are available
dependencies=( pdftoppm convert )
for dependency in "${dependencies[@]}"; do
  command -v $dependency >/dev/null 2>&1 || { echo >&2 "‘$dependency’ command is required but it’s not installed. Aborting."; exit 1; }
done

# Create a directory to hold extracted images
if [ ! -d "images" ]; then
  mkdir images
else
  rm -R images/*
fi

# Make sure there’s an argument provided
if [ -z "$1" ]; then
  echo "Error: no filename supplied."
  exit 1
fi
SOURCEPDF=$1
FILENAME=$(echo "$SOURCEPDF" | cut -f 1 -d '.')

echo "Converting PDF pages to images..."
pdftoppm -png "$SOURCEPDF" images/out

echo "Converting images to PDF..."
cd images || exit 1
convert $( ls ) "../$FILENAME -PROOF IMAGE - DO NOT PRINT.pdf"
cd ../ || exit 1

# Tidy up, removing generated images
rm -R images

Homebrew-installable version available here: https://github.com/delucis/pdf2imgpdf