optimize jpg with jpegoptim

gulpfile.babel.js

@@ -9,6 +9,7 @@ import browser      from 'browser-sync'
 import autoprefixer      from 'autoprefixer'
 import cssnano           from 'cssnano'
 import critical          from 'critical'
+import imageminJpegoptim from 'imagemin-jpegoptim'
 
 // load plugins
 const $ = plugins()
@@ -250,29 +251,24 @@ export const icons = () => src(iconset.icons)
 //
 // Images
 //
+const imageminPlugins = [
+    $.imagemin.gifsicle({ interlaced: true }),
+    imageminJpegoptim(),
+    $.imagemin.optipng({ optimizationLevel: 5 }),
+    $.imagemin.svgo({ plugins: [{removeViewBox: false }]})
+]
+
 export const images = () =>
     src([
         SRC + '/_assets/img/**/*',
         '!' + SRC + '/_assets/img/entypo'
     ])
-    .pipe($.if(isProduction, $.imagemin({
-        optimizationLevel: 5, // png
-        progressive: true, // jpg
-        interlaced: true, // gif
-        multipass: true, // svg
-        svgoPlugins: [{ removeViewBox: false }]
-    })))
+    .pipe($.if(isProduction, $.imagemin(imageminPlugins)))
     .pipe(dest(DIST + '/assets/img/'))
 
 // optimize Jekyll generated images
 export const imagesGenerated = () => src(DIST + '/media/gen/**/*')
-    .pipe($.if(isProduction, $.imagemin({
-        optimizationLevel: 5, // png
-        progressive: true, // jpg
-        interlaced: true, // gif
-        multipass: true, // svg
-        svgoPlugins: [{ removeViewBox: false }]
-    })))
+    .pipe($.if(isProduction, $.imagemin(imageminPlugins)))
     .pipe(dest(DIST + '/media/gen/'))
 
 

package.json

@@ -53,7 +53,8 @@
     "gulp-stylus": ">=2.3.1",
     "gulp-svg-sprite": ">=1.2.2",
     "gulp-uglify": ">=1.2.0",
-    "gulp-util": ">=3.0.6"
+    "gulp-util": ">=3.0.6",
+    "imagemin-jpegoptim": ">=5.0.0"
   },
   "engines": {
     "node": ">=5.0.0"