image_optimizer.sh

#!/bin/bash
# vim:fenc=utf-8 ff=unix ft=sh et sts=4 sw=4 ts=4:
 set -e
 set -u
#set -x

PATH=/usr/local/bin:/usr/bin:/bin

: ${QUALITY:=90}


log(){
    echo "$(date -Is) ${*}" | tee /dev/fd/2 | logger -t "${0##*/}"
}

convert(){( i=${1:?} s=${2:?} o=${3:?}
    convert "${i}" -quality 100 -filter Lanczos2 -resize ${s}x${s} ${o}:-
)}

cwebp(){( p=${1:?}
    test -d     "${p%/*}" \
    || mkdir -p "${p%/*}"

    cwebp -quiet -q ${QUALITY} -o "${p}" -- -
)}

jpegoptim(){( p=${1:?}
    test -d     "${p%/*}" \
    || mkdir -p "${p%/*}"

    jpegoptim --quiet --stdin --stdout --strip-all -m${QUALITY} >"${p}"
)}


log "画像最適化スクリプト起動"

! pgrep -f "${0##*/}" >/dev/null || { log "多重起動を検出しました。処理を終了します"; exit 1; }

type convert   >/dev/null 2>&1 || { log "$_ not found."; exit 1; }
type cwebp     >/dev/null 2>&1 || { log "$_ not found."; exit 1; } 
type jpegoptim >/dev/null 2>&1 || { log "$_ not found."; exit 1; }

cd "${1:?}"
srcdir=$(pwd)
cd ..
dstdir_jpeg_s=save_image_jpeg_s
dstdir_jpeg_m=save_image_jpeg_m
dstdir_webp_s=save_image_webp_s
dstdir_webp_m=save_image_webp_m

set -- "${srcdir}"/*

log "チェック対象 ${#} ファイル from \"${srcdir}\""
log "最適化開始"

for f
do
    test -f "${f}" || continue

    srcname=${f##*/}

    case ${srcname##*.} in
    jpg|jpeg|png|\
    JPG|JPEG|PNG)
        :
    ;;
    *)
        continue
    ;;
    esac

    dstpath_jpeg_s=${dstdir_jpeg_s}/${srcname}_s.jpg
    dstpath_jpeg_m=${dstdir_jpeg_m}/${srcname}_m.jpg
    dstpath_webp_s=${dstdir_webp_s}/${srcname}_s.webp
    dstpath_webp_m=${dstdir_webp_m}/${srcname}_m.webp

    test : \
    -a   -s "${dstpath_jpeg_s}"            \
    -a      "${dstpath_jpeg_s}" -nt "${f}" \
    -a   -s "${dstpath_jpeg_m}"            \
    -a      "${dstpath_jpeg_m}" -nt "${f}" \
    -a   -s "${dstpath_webp_s}"            \
    -a      "${dstpath_webp_s}" -nt "${f}" \
    -a   -s "${dstpath_webp_m}"            \
    -a      "${dstpath_webp_m}" -nt "${f}" \
    && continue || :

    # JPEG
    log "${f} -> ${dstpath_jpeg_s}"
    convert "${f}" 240 jpg | jpegoptim "${dstpath_jpeg_s}" &
    log "${f} -> ${dstpath_jpeg_m}"
    convert "${f}" 800 jpg | jpegoptim "${dstpath_jpeg_m}" &
    wait

    # WebP
    log "${f} -> ${dstpath_webp_s}"
    convert "${f}" 240 png | cwebp     "${dstpath_webp_s}" &
    log "${f} -> ${dstpath_webp_m}"
    convert "${f}" 800 png | cwebp     "${dstpath_webp_m}" &
    wait

    sleep 0.1
done; unset f

log "最適化終了"
log "$(printf '%s\n%s' "du -sh *" "$(du -sh * | column -t)")"
log "$(printf '%s\n%s' "df -h"    "$(df -h)"               )"