Recursive bash ImageMagick thumbnail generation tool

make-thumbs

#!/bin/bash

declare -a EXTS=("jpg" "jpeg" "png" "gif")
DEBUG=0
WIDTH=100
HEIGHT=100
OUT_DIR=""
SUFFIX=""
INPUTS=()

usage() {
  echo ""
  echo "Usage: $0 <input> -o <out-dir> [ -w <width> -h <height> -s <suffix> -d ]"
  echo ""
  echo "Explanation: Recursively generates thumbnails with ImageMagick from a \
specified input path to an output directory, replicating the same relative tree."
  echo ""
  exit 2
}

run() {
  parseOptions $@
  validateOptions
  debugOptions
  generateThumbnails
}

relativePath() {
  s=$(cd ${1%%/};pwd); d=$(cd $2;pwd); b=; while [ "${d#$s/}" == "${d}" ]
  do s=$(dirname $s);b="../${b}"; done; echo ${b}${d#$s/}
}

debug() {
  if [ $DEBUG == 1 ]
  then
    for value in "${@}"
    do
      echo -e $value
    done
  fi
}

debugOptions() {
  debug "\n
  +-----------------+\n
  |++++ Options ++++|:\n
  +-----------------+\n
  \n
  - Width: ${WIDTH}\n
  - Height: $HEIGHT\n
  - Inputs: ${INPUTS[*]}\n
  - Output: ${OUT_DIR}\n
  - Suffix: ${SUFFIX}\n
  "
}

parseOptions() {
  while [ $# -gt 0 ]
  do
    unset OPTIND
    unset OPTARG
    while getopts "w: h: o: s: d"  options
    do
    case $options in
      h)
        if [ ! -z "$OPTARG" ]
        then
          HEIGHT=$OPTARG
        else
          usage
        fi
        ;;
      w)
        WIDTH=$OPTARG
        ;;
      o)
        OUT_DIR=$OPTARG
        ;;
      s)
        SUFFIX=$OPTARG
        ;;
      d)
        DEBUG=1
        ;;
      ?)
        usage
        ;;
    esac
   done

   shift $((OPTIND-1))
   INPUTS=(${INPUTS[@]} $1)
   shift
  done
}

validateOptions() {
  if [ ${#INPUTS[@]} -eq 0 ]
  then
      echo "Please specify at least one input dir"
      usage
  fi

  if [ -z $OUT_DIR ]
  then
    echo "Please specify an output directory with -o"
    usage
  fi

   if [ ! -d $OUT_DIR ]
   then
     echo "Output directory \"${OUT_DIR}\" doesn't exist"
     exit 1
   fi
}

generateThumbnails() {
  for input in "${INPUTS[@]}"
  do
    debug "Processing input: ${input}..."

    if [ ! -d $input ]
    then
      echo "Output directory \"${input}\" doesn't exist"
      exit 1
    fi

    for file in $(find $input -name '*.*')
    do
      ext="${file##*.}"


      if [[ " ${EXTS[@]} " =~ " ${ext} " ]]; then
        debug "Processing file: ${file}..."
        relativePath=$(relativePath $input $(dirname $file))
        outPath="${OUT_DIR}/${relativePath}"
        thumbnailPath="${outPath}/$(basename $file ".${ext}")${SUFFIX}.${ext}"
        mkdir -p $outPath
        convert -thumbnail "${WIDTH}x${HEIGHT}^" -gravity center -extent "${WIDTH}x${HEIGHT}" $file $thumbnailPath
        debug "Generated ${thumbnailPath}"
      fi
    done
  done

  debug "\nDone"
}

run $@