Patent ID: 6094228
Filing Date: 2000-07-25
Classification: H04N

Abstract:
A method of superimposing data on the visible portion of a video signal comprising the steps of:(a) converting an input video signal to a digital representation thereof;(b) for each of a multiplicity of data symbols, assigning a respective chip pattern having more chips than the number of bits represented by said each data symbol, each chip pattern having a plurality of lines, each with a plurality of chips, to be superimposed on said video signal in paired lines having respective normal and inverse forms;(c) developing a chip amplitude table having digital values that represent the values of respective chips to be superimposed on said video signal at corresponding positions thereof;(d) deriving a digital representation of an output video signal by digitally adding the representation of said input video signal and the chip values represented in said chip amplitude table at the corresponding positions thereof;(e) simulating the decoding of data superimposed on said output video signal by operating digitally on the digital representation derived in step (d);(f) increasing values in said chip amplitude table if the simulated decoding of step (e) produces erroneous results; and(g) after values in said chip amplitude table have been increased such that a simulated decoding of step (e) produces correct results, generating an output video signal from the digital representation of said input video signal and the chip values represented in said chip amplitude table at the corresponding positions thereof.