If a hanging portrait suddenly smiles back at you, it might be something you've eaten, but it might also be HenGenTou – a new light projection technique developed by NTT Communication Science Laboratories that magically brings static objects like paintings to life.
Projection mapping (known as Shader Lamps), where a real object is overlaid with a projected image, is both costly and technically difficult to achieve, according to NTT Communication Science Laboratories. For this reason, the lab developed what they call HenGenTou, which means "Deformation Lamps" in Japanese.
HenGenTou works by projecting a grey-scale pattern onto a static picture in the general shape of the part of the image that is required to be seen to change or move. Movement is added to this light, which the human brain then interprets as a movement of the image underneath. This illusory approach which preserves the real or existing image (as opposed to physically changing the appearance of the target), adds up to a system that requires less computation than standard projection mapping techniques and is therefore much cheaper.
The human brain interprets this trick of a light as movement of the real image underneath because color and form information are received on a different path to motion information. So when the human brain makes a coherent visual picture of a scene by combining color and form together with motion, it automatically corrects the small amounts of misalignment and anomalies among its sources. The result is that we perceive the pattern produced by HenGenTou as changes in the color and form in the static picture we are looking at.
HenGenTou can be used in under bright ambient lighting conditions and the researchers say that the technique can also be applied to 3D objects, though it is a lot more difficult to achieve and there are restrictions on the viewing conditions under which it will be effective (i.e. you need to stand directly in front).
NTT sees practical applications for HenGenTou in areas such as advertising, where a smiling face or fluttering text on a static sign would certainly be eye-catching event, and interior design, where the illusion of an undulating flow of water or rising heat waves could be created on floors and walls.
Gizmag recently checked out the new technique at the annual NTT R&D forum and there is promise of a public demonstration of the art of HenGenTou later in 2015. The overall aim is to have this technology fully developed for the 2020 Olympics in Tokyo, after which it will become commercially available.
In the meantime, you can see the magical HenGenTou effect in the video below.