Improved Perlin noise "too smooth"
<p>I've finally managed to write a working Lua version of Perlin's improved noise for Love 2D. However, when I run it, I get this:</p>

<p><a href="https://i.stack.imgur.com/emhzM.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/emhzM.jpg" alt=""></a></p>

<p>Which is just fine, I guess. But I would like something that looks more like this:</p>

<p><a href="https://i.stack.imgur.com/6KrOP.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6KrOP.jpg" alt=""></a></p>

<p>How can I achieve this?</p>