EmiTable: A Tabletop Surface Pervaded with Imperceptible Metadata

This paper proposes a novel tabletop display named "EmiTable" that can emit imperceptible metadata along with the tabletop image. Actually, our system displays a visual image on the tabletop whose pixels contain metadata as bit patterns for dedicated receivers. Since the bit patterns are embedded as high-speed flickers, the users would not perceive the hidden signal behind the image. However, we can read out the metadata by putting stand-alone receivers on the tabletop. Since the hidden signal is embedded independently in each pixel, different metadata can be drawn according to the position on the tabletop. The advantage of our system is that it can superimpose metadata which are strongly related to the image content in an imperceptible way. This paper presents the detailed design and several applications.