Convert image files into smaller thumbnails using Imagemagick

thumbnailer.sh

#! /bin/bash
#
# Recursively convert image files in IN_DIR into smaller jpegs
# Copy all other files straight over
# Resulting files (including folder structure) ends up in in IN_DIR/../thumbs/

IN_DIR=$1

is_image() {
  local name=$1
  file "$name" | grep image > /dev/null
}

#replicate dir structure

pushd "$IN_DIR"
mkdir -p "../thumbs"

find . -type d ! -name .| while read DIR;  do
  mkdir -p "../thumbs/${DIR}"
done

#convert files

find . -type file| while read FILE; do
  if is_image "$FILE"; then
    convert "$FILE" -resize 60x60% -quality 70 -format jpg "../thumbs/${FILE}"
  else
    cp "$FILE" "../thumbs/${FILE}"
  fi
done

popd