#!/bin/bash
name=$1
gs \
  -sDEVICE=pdfwrite \
  -sProcessColorModel=DeviceGray \
  -sColorConversionStrategy=Gray \
  -sColorImageResolution=600 \
  -sColorImageFilter=/FlatEncode \
  -dOverrideICC \
  -dCompatibilityLevel=1.4 \
  -dAutoRotatePages=/None \
  -o "$name-grey.pdf" \
  "$name"