images.js

var gulp = require('gulp'),
    newer    = require('gulp-newer'),
    imagemin = require('gulp-imagemin'),
    notify   = require('gulp-notify'),
    webp     = require('gulp-webp');

gulp.task('images', function() {
	
  var source = './source/images',
      destination = './deploy/i';
	
  // Optimize & move
  gulp.src( source + '/**/*.{jpg,png,svg,gif}')
    // Only new stuff
    .pipe(newer(destination))
    // Optimize
    .pipe(imagemin())
    // Copy
    .pipe(gulp.dest(destination))
    ;

  // Make WebP versions or PNG & JPG
  gulp.src(source + '/**/*.{jpg,png}')
    // Only new stuff
    .pipe(newer(destination))
    // WebP
    .pipe(webp())
    // Publish
    .pipe(gulp.dest(destination))
    ;
  
  return true;
  
});