Light Codes

Visual codes such as QR codes are widely used in several applications for conveying information to users. However, user interactions based on spatial codes (e.g., displaying codes on phone screens for exchanging contact information) are often tedious, time consuming, and prone to errors due to image corruptions such as noise, blur, saturation and perspective distortions. We propose Light Codes, a novel method for fast and fluid exchange of information among users. Light Codes are based on transmitting and receiving temporal codes (instead of spatial) using compact and low-cost transceiver devices. The resulting approach enables seamless and near instantaneous exchange of short messages among users with minimal physical and cognitive effort. We design novel coding techniques, hardware prototypes and applications that are optimized for human-centric communication, and facilitate fast and fluid user-to-user interactions in various challenging conditions, including a range of distances, motion and ambient illumination. We evaluate the performance of the proposed methods both via quantitative analysis, as well as user-study-based comparisons with several existing approaches including display-camera links, Bluetooth and NFC, which show strong preference toward Light Codes in various real-world application scenarios.