Unveil

#unveil.js ###A very lightweight plugin to lazy load images for jQuery or Zepto.js

Most of us are familiar with the [Lazy Load](http://www.appelsiini.net/projects/lazyload) plugin by [Mika Tuupola](http://www.appelsiini.net/). This plugin is very useful and it boosts performance delaying loading of images in long web pages because images outside of viewport (visible part of web page) won't be loaded until the user scrolls to them. Lazy Load has some cool options such as custom effects, container, events or data attribute. If you're not gonna use any of them you can reduce the file size by leaving just the essential code to show the images. That's what I did and this is my lightweight version of Lazy Load with support for serving high-resolution images to devices with retina displays - less than 1k.

Visit unveil's [project page](http://luis-almeida.github.com/unveil/) to read the documentation and see the demo.

Usage

Use a placeholder image in the src attribute - something to be displayed while the original image loads - and include the actual image source in a "data-src" attribute. If you want to serve high-resolution images to devices with retina displays, you just have to include the source for those images in a "data-src-retina" attribute. You don't need to include a "data-src-retina" attribute in all the image tags, unveil is smart enough to fallback to "data-src" or even do nothing in case there isn't any "data-src" specified.

If you care about users without javascript enabled, you can include the original image inside a ```noscript``` tag:

Run the script on document ready:

$(document).ready(function() {
  $("img").unveil();
});

###Threshold By default, images are only loaded and "unveiled" when the user scrolls to them and they became visible