Embedding imperceptible codes into video projection and applications in robotics

We describe a method of embedding imperceptible codes, that are for structured light sensing (SLS), into regular display in video projection. To resolve the conflict between imperceptibility of the embedded codes and feasibility and robustness of SLS code retrieval, we introduce antinoise schemes to the coding and decoding stages simultaneously. On one hand, specially designed primitive shapes and large Hamming distance are employed in the spatial SLS coding to enhance the error-tolerance capability. On the other hand, pre-trained primitive shape detectors are applied to detect and identify the embedded codes in the decoding stage - a task difficult to achieve by segmentation that is adopted in classical structured light methods, when weakly embedded information is inevitably interfered by noise. Extensive experiments show that the proposed method is effective and accurate in code retrieval, even with the prerequisite of incurring minimum disturbance to arbitrary video projection. Some potential applications to a robotic system are also demonstrated.