Using a placeholder image before loading the full image
<p>What is the correct way to use a placeholder image?</p>

<p>I want to fill a UIScrollView with images as subviews, but it has been to heavy on the older devices to load in all the full images before showing the scrollview.</p>

<p>How can a placeholder image be used so that I can load in the full image when the user scrolls to that contentOffset?</p>

<p>I tried using the thumbnail of the ALAsset, but the scaling looks horrible.</p>
