Scrolling A Message On A Building In A Time Lapse Video

[Saulius Lukse] has a really interesting way of turning a couple of buildings into his own addressable display. The effect is not seen in real life, but is a clever video rendering with stock he pulled from time-lapse cameras. Now if you want to play Tetris using the windows of a building you add wireless lightbulbs to every window. But that’s a lot of work. You can fake playing Tetris (or scrolling messages in this case) if you just show a video of the buildings and swap in your own image manipulation.


[Saulius] starts with a time lapse sequence of a city scape. It needs to be one with a large building or two to provide a good scrolling surface. The building is extracted from the scene with the background transparent. The really time consuming part is creating a distinct image with one window lit for each window that is going to be used. This set of windows are the ‘pixels’ used to create the scrolling images. This is accomplished by masking out one image of the building with every office light turned off, then masking out each window individually with the office illuminated. This masking means everything going on around the building (traffic, weather, people) will be preserved, while the windows can be individually manipulated.

Next the program jinx is used to create the building animation. This program is designed to create scrolling messages on LED panels. [Saulius] provides a Python script that takes the images, the output of jinx, and combines them to create the final set of moving images.

The result is a city wishing you a “Happy New Year!”

12 thoughts on “Scrolling A Message On A Building In A Time Lapse Video

  1. And the grumpy old geezer on the 6’th floor yelled “no one home” when the gaffas came knocking on his door before the concert to install the lights in his living room.

    1. Actually at 5:53 it joins the rest of the sequence, it just seems to have got stuck dropped off the light network until then. That or someone went up and installed a light there 5 minutes in.

    1. As with many New Yorker cartoons, I don’t think I get it. So the office workers have a near deadline, which causes them to turn on the lights in the shape of a cross. Are they trying to court divine favor? Is the building supposed to look like a tombstone?

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