Turn your image into 1x1px DIV element. You see it on screen but can't grab it like an image, literally Ghost.
Check out the Demo Site
Made by @kosamari. Inspired by Vince Allen's Pixel Art and Complex Systems talk.
App use HTML5 Canvas to get color data from an image. The data collected is then transformed into chain of CSS box-shadow to create "ghost image" of 1x1px DIV element.