The question

I think scanner cameras, and the resulting images, are fascinating.

I don't have any scanner camera, and the likelihood of me buying or building and operating one is extremely near zero.

Yet, I find experimenting with the concept of such cameras exciting, which is why I've created this site. But how can one create scanner camera like images such as the one below, without having the appropriate camera for the task?

Skvallertorget, Norrköping, Sweden

The answer

In one word: Cheat!

A scanner camera is not magic, contrary to what the resulting images suggest. If you accept a number of limitations, its basic behavior can be emulated with a regular movie camera, combined with massive amounts of CPU and disk.

The above image was created by capturing a little bit less than 43 seconds of video (1280 frames), which was then split into individual frames. Those frames were, in turn, split into one-pixel columns, each 720 pixels high.

The scanner camera's amazing images stem from the fact that it samples one column of pixels, then moves to and samples the next column, and so on. What we need to do in order to emulate this is to build an image containing the first pixel column from the first image, the second column from the second image, until we've reached the last column. The result looks very much like a scanner image, scanned during the time of almost 43 seconds; 30 columns per second.

The movie

The scanner movie camera has quite a few limitations that a real scanner camera doesn't have; among those are:

On the other hand, it doesn't have all of the limitations a real scanner camera has:

...well, that's probably about it. But that single point is what makes it possible to use the same scanner to make 1280 simultaneous passes over the image, each displaced one pixel and 1/30 second from each other. Using those virtual, parallel scanners makes it possible to create a full framerate video consisting of scanner images, while a real scanner camera is limited to timelapse photography.


Questions or comments?

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