Hidden images

Most coloured objects and prints have constant colours whatever the illumination and viewing conditions are. However, it is possible to change dramatically the colour aspect of surfaces according to the way they are illuminated or observed, by using ingenious photonics techniques. The domain in which this principle has been the most investigated is the security-printing domain in order to protect documents against counterweighting. However, one might imaging innovative concepts of decorative objects, for example lampshades displaying some patterns at daytime and different patterns at night-time.


The project aims at producing a light board, which displays an image in certain lighting/viewing conditions that is not visible in other conditions.