The easiest way is... <a href="https:&#x2F;&#x2F;deepart.io&#x2F;" rel="nofollow">https:&#x2F;&#x2F;deepart.io&#x2F;</a>. Open source: <a href="https:&#x2F;&#x2F;github.com&#x2F;jcjohnson&#x2F;neural-style" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;jcjohnson&#x2F;neural-style</a> (not sure if exactly this one, there are a few implementations).