Script to create 2000x thumbnails from Canon RAW images, and store those in same hierarchy under "thumbs" folder. Also preserves metadata info from original RAW.

generate-thumbs.sh

#!/bin/sh
set -e
cd /mnt/usb/
for d in */; do
  echo $d
  if [ ! -d "$d/thumbs" ]; then
    echo "generating thumbs"
    exiftool -b -PreviewImage  -w "$d/thumbs/%f.jpg" -ext CR2 -r "$d"
    exiftool -tagsfromfile "$d/%f.CR2" -all:all -r -overwrite_original -ext jpg "$d/thumbs"
    mogrify "$d/thumbs/*.jpg" -resize 2000x "$d/thumbs/*"
  else
    echo "has thumbs, skipping"
  fi
done