Structured light sensing, as one of the most traditional 3D reconstruction methods, has been studied extensively in computer vision society. And during the last few years, there are many so-called pico-projectors launched to the market, which have extremely small size and low cost, yet with adequate performance. This kind of pico-projector has been already embedded into many consumer electronic devices (Mobile Phone, Digital Camera(DC) and Digital Video Recorder) Such projector-camera system in the mobile devices can make the structured light sensing technologies everywhere. However, in traditional methods, the visible structured patterns will change the appearance of environment and disturb the users' feeling.

Some researchers designed structured light system in the non-visible spectrum. That way the media for regular projection and structure light sensing can be made separate. However, additional hardware could be reduced and device size could be diminished if structured light and regular projection can be achieved through the same projector. This leads to the concept of Imperceptible Structured Light (ISL). However, There is still challenging work in embedding codes into regular projection. While the codes should be made as undetectable as possible to the user, they have to be decodable to the camera for the purpose of structured light sensing. The objective of this work is to deal with this dilemma.

Principle of Embedding Imperceptible Codes

Coding

Decoding

Primitive Shape Detector Training

System Setup

Imperceptibility Evaluation

Primitive Shape Detection Accuracy Evaluation

3D reconstruction

Integration with Mobile Robot

[1] J. Dai and R. Chung. Embedding Invisible Codes into Normal Video Projection: Principle, Evaluation and Applications. IEEE Transactions on Circuit and System for Video Technology, In Press, 2013.
[2] J. Dai and R. Chung. On Making Projector both a Display Device and a 3D Sensor. In Proc. of The 8th International Symposium on Visual Computing, pages 654-664, 2012.
[3] J. Dai and R. Chung. Embedding Imperceptible Codes into Video Projection and Applications in Robotics. In Proc. of IEEE/RSJ International Conference on Intelligent Robots and Systems, pages 4399-4404, 2012.