Imagemin task added on assets

Gruntfile.js

 module.exports = function(grunt) {
+
+  var mozjpeg = require('imagemin-mozjpeg');
+
   grunt.initConfig({
     pkg: grunt.file.readJSON('package.json'),
 
@@ -142,6 +145,19 @@ module.exports = function(grunt) {
         src: ['index.html'],
       }
     },
+
+    imagemin: {
+      dynamic: {
+        files: [{
+          expand: true,
+          cwd: 'assets/',
+          src: ['**/*.{png,jpg,gif}'],
+          dest: 'assets/'
+        }]
+      }
+    },
+
+
 /**
  * X :: Watch files for changes and act on them (recompile etc...).
  */
@@ -167,6 +183,11 @@ module.exports = function(grunt) {
       svg: {
         files: 'svg/**/*.svg',
         tasks: ['svgstore']
+      },
+
+      images: {
+        files: ['**/*.{png,jpg,gif}'],
+        tasks: ['imagemin'],
       }
     }
 
@@ -175,7 +196,7 @@ module.exports = function(grunt) {
   // Load necessairy grunt tasks based on npm modules.
   require("load-grunt-tasks")(grunt);
 
-  grunt.registerTask('critical', ['uglify', 'svgstore', 'sass', 'concat_css', 'autoprefixer', 'php2html', 'penthouse' ,'inline', 'cssmin']);
-  grunt.registerTask('build', ['uglify', 'svgstore', 'sass', 'concat_css', 'autoprefixer', 'cssmin']);
+  grunt.registerTask('critical', ['uglify', 'svgstore', 'sass', 'concat_css', 'autoprefixer', 'php2html', 'penthouse' ,'inline', 'cssmin', 'imagemin']);
+  grunt.registerTask('build', ['uglify', 'svgstore', 'sass', 'concat_css', 'autoprefixer', 'cssmin', 'imagemin']);
   grunt.registerTask('default', ['build','watch']);
 }

package.json

@@ -7,6 +7,7 @@
     "grunt-autoprefixer": "^1.0.1",
     "grunt-concat-css": "^0.3.1",
     "grunt-contrib-cssmin": "^0.10.0",
+    "grunt-contrib-imagemin": "^0.9.2",
     "grunt-contrib-uglify": "^0.6.0",
     "grunt-contrib-watch": "~0.5.3",
     "grunt-inline": "^0.3.2",
@@ -14,6 +15,7 @@
     "grunt-php2html": "^0.1.17",
     "grunt-sass": "~0.8.1",
     "grunt-svgstore": "^0.3.5",
+    "imagemin-mozjpeg": "^4.0.0",
     "load-grunt-tasks": "^0.6.0",
     "node-sass": "~0.9.3"
   }