Our method is based on a simple premise: neighboring pixels in space-time that have similar intensities should have similar colors. We formalize this premise using a quadratic cost function and obtain an optimization problem that can be solved efficiently using standard techniques. In our approach an artist only needs to annotate the image with a few color scribbles, and the indicated colors are automatically propagated in both space and time to produce a fully colorized image or sequence. We demonstrate that high quality colorizations of stills and movie clips may be obtained from a relatively modest amount of user input.

This is an exciting technology that has to find it's way into the next version of PhotoShop. It's so simple and powerful. The same job can be done with the current version of PS, but it would be a tedious work to get it done right. With some experience and skill I can see this technology could help create some very interesting effects.