Patent ID: 8662398

Claim:
A method comprising: displaying by a first device a first sender pattern, the first sender pattern representing data comprising a first sender sequence number; obtaining, by the first device, an acknowledgement image displayed by a second device, wherein the acknowledgement image comprises a first receiver pattern, the first receiver pattern representing data comprising a function of the first sender sequence number and a first receiver sequence number; displaying by the first device a second sender pattern, the second sender pattern representing data comprising a function of the first receiver sequence number and a function of the first sender sequence number; displaying by the first device a sequence of sender patterns, each sender pattern representing data comprising a sender sequence number, a sender acknowledgement number, and sender payload data; obtaining, by a camera of the first device, a sequence of images displayed by the second device, wherein each image comprises a receiver pattern representing data comprising a receiver sequence number, a receiver acknowledgement number and receiver payload data; arranging, based on corresponding receiver sequence numbers, receiver payload data from a plurality of receiver patterns to form received data; and processing the received data at the first device.