Bokode is an imperceptible visual tag that encodes directional information for camera-based interaction from a distance. It uses an invisible barcode pattern to the human eye but can be decoded by a machine. When captured by a camera, the angle and position of the Bokode within the image allows extraction of encoded data as well as the camera's angle relative to the Bokode. This enables applications such as surface interaction, multi-user interaction, and augmented reality without requiring direct line of sight.

1. Bokode: ankit mohan, grace woo, shinsaku hiura, quinn smithwick, ramesh raskar camera culture group, MIT media lab imperceptible visual tags for camera based interaction from a distance

4. ideal barcode invisible to the human eye ; easily decodable by a machine. Bokode

5. visible light barcodes space [UPC Code, QR Code, Data Matrix Code, Shot Code, Microsoft Tag, …] angle Bokode – this paper standard camera focused at infinity + time [IR remote, Sony ID CAM]

6. barcode ( spatial) camera sensor

7. camera sensor barcode ( space)

9. sensor Bokode ( angle) camera

11. Bokode f b generate directionally encoded information

12. Bokode camera f b capture directionally encoded information f c

14. Bokode: any barcode pattern datamatrix code (42,245,123)

15. tiled datamatrix codes

16. identity from Bokode id = (42,245,123)

17. prototype – assembled

18. prototype – exploded led: 120 ° view angle, 1350mcd pattern: 15µm resolution lenslet: f=8mm, Φ=3mm cost: ~$5

19. capturing Bokodes focus blur (85mm f/1.8; infinity focus) motion blur (50mm f/8; ~2cm motion)

20. street-view tagging

21. capturing Bokodes cell-phone camera close to the Bokode (10,000+ bytes of data)

25. Bokode camera f b f c less distance  more of Bokode imaged

26. less distance  more of Bokode imaged Bokode camera f b f c

27. Bokode f b Bokode image depends on camera angle camera

28. Bokode f b f c Bokode image depends on camera angle camera

29. camera x y id=42 x=9 y=5 id=42 x=9 y=6 id=42 x=9 y=7 id=42 x=7 y=5 id=42 x=7 y=6 id=42 x=7 y=7 id=42,x=8,y=7 id=42,x=8,y=5

30. digital angle from Bokode id = (42, 10,7 )

32. traditional AR markers ARToolKit [ Kato and Billinghurst 1999] ARTag [ Fiala 2005] skew of marker

33. angle estimation robustness

35. retro-reflector for passive Bokode

36. wide field of view Bokode via Krill eye compound superposition optics [Hiura et al. 2009]

38. barcode RFID Bokode encoding spatial rf modulation angular decoder camera dedicated reader camera geometry no no yes physical size ~ cm ~ cm ~ mm cost ~ free ~ $0.05 ~ $0.05 (currently $5) range ~ cm ~ cm ~ m (with large aperture lens) line of sight yes no yes

39. user interaction applications

41. multi-user interaction Bokode laser pointers

43. acknowledgements meng heng touch, donald eng, daniel taub paula aguilera, eugene wu andy lippman masahiko inami frank moss