  Digital videos such as those captured by a smartphone often exhibit exposure
inconsistencies, a poorly exposed sky, or simply suffer from an uninteresting
or plain looking sky. Professionals may edit these videos using advanced and
time-consuming tools unavailable to most users, to replace the sky with a more
expressive or imaginative sky. In this work, we propose an algorithm for
automatic replacement of the sky region in a video with a different sky,
providing nonprofessional users with a simple yet efficient tool to seamlessly
replace the sky. The method is fast, achieving close to real-time performance
on mobile devices and the user's involvement can remain as limited as simply
selecting the replacement sky.
