TYPO3 CMS Extension "lib_jquery_lazyload"
In your fluid-template use something like this:
{namespace lazy=Sonority\LibJqueryLazyload\ViewHelpers}
<lazy:image
src="{mediaElement.uid}"
treatIdAsReference="1"
title="{mediaElement.title}"
alt="{mediaElement.alternative}"
maxWidth="{settings.detail.media.image.maxWidth}"
maxHeight="{settings.detail.media.image.maxHeight}"
class="img-lazy img-responsive"
/>