Method for transmitting data on viewable portion of a video signal

• US 6,229,572 B1
• Filed: 03/27/2000
• Issued: 05/08/2001
• Est. Priority Date: 10/28/1997
• Status: Expired due to Term

• Current Assignee: Koplar Interactive International LLC
• Original Assignee: Koplar Interactive International LLC
• Inventors: Kosbar, Kurt Louis, Chupp, Christopher Eric, Ciardullo, Daniel Andrew
• Primary Examiner(s): Kostak, Victor R.
• Application Number:
  US09/535,401
• Time in Patent Office: 407 Days
• Field of Search: 343/473, 343/476, 343/469, 343/553, 343/564, 343/478
• US Class Current: 348/473
• CPC Class Codes: H04N 7/025 Systems for the transmission of digital non-picture data, e.g. of text during the active part of a television frame transmission of digital non-picture data during the vertical blanking interval only H04N7/088
• CPC Class Codes: H04N 7/035 Circuits for the digital non-picture data signal, e.g. for slicing of the data signal, for regeneration of the data-clock signal, for error detection or correction of the data signal
• CPC Class Codes: H04N 7/08 Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band , e.g. by time division H04N7/007 takes precedence

Abstract

A method of encoding data in the visible portion of a transmitted video signal without degrading display of the received video signal, and for decoding the data in the received video signal. Each group of data bits to be transmitted, referred to a data symbol, is associated with one of a number of longer predetermined sequences of chips. Each chip sequence is divided into a multiplicity of lines of chips, and each line of chips together with its inverse are embedded, in pairwise fashion, in respective pairs of line scans of the video signal prior to its transmission. Received pairs of line scans are operated upon to detect the lines of chips they represent, and each of the number of chip sequences is correlated with the detected line of chips to derive a correlation magnitude. The chip sequence with the largest correlation magnitude is selected as the chip sequence whose data symbol was transmitted.

Claims

1. A method of transmitting data including a plurality of data symbols on a video channel on which video signals are transmitted, said video signals being composed of sequential visible video lines, said method comprising the steps of:

assigning a plurality of chips to each symbol;

generating line pairs for each symbol, each line pair corresponding to a set of chips selected from said plurality of chips, each line pair including a first line having a first polarity and a second line with a plurality opposite said first plurality; and

combining each line pair with a two sequential video lines to generate combined video signals.

2. The method of claim 1 further comprising defining a chip table and using said chip table to include opposite polarity chips in paired lines.

3. The method of claim 2 wherein in said chip table defines chips of different magnitudes.

4. The method of claim 1 further comprising the step of:

decoding said combined video signal by separating said chips from said visible video lines.

5. The method of claim 4 wherein the decoding includes deriving the difference of the integrals of the video signal operated upon over the course of each pair of opposite polarity chips, and statistically correlating each of said chip patterns with the integral differences to determine the highest correlation.

6. The method of claim 5 further providing a chip amplitude table to derive said chip pattern wherein said chip amplitude table includes opposite polarity chips in paired lines in said combined video signal.

7. A method of encoding data in the visible portion of a transmitted video signal without degrading display of the received video signal and for decoding said data in the received video signal, comprising the steps of:

(a) selecting for a group of data bits to be transmitted an associated one of a number of longer predetermined sequences of chips,

(b) dividing the selected sequence of chips into a multiplicity of lines of chips,

(c) embedding each line of chips and its inverse, in pairwise fashion, in respective pairs of line scans of said video signal prior to its transmission, and

(d) selecting a chip sequence which corresponds to the imbedded chips.

8. A method in accordance with claim 7 wherein in step (c) the two possible values of a chip cause changes in a characteristic of the video signal in respective opposite directions.

9. A method in accordance with claim 8 wherein one line scan in each pair of line scans operated upon is subtracted from the other line scan in the same pair in order to reduce the effect of the video signal on, and to increase the amplitude of, the detected line of chips.

10. A method in accordance with claim 8 wherein each line scan is operated upon by deriving an integration function for each chip, and each chip function for one line scan is subtracted from a chip function for a correspondingly positioned chip in the paired line scan.

11. A method in accordance with claim 10 further including the steps of embedding a synchronizing chip pattern in a number of line scans of said video signal prior to its transmission, and operating on the received video signal to determine the position of the synchronizing chip pattern in order to ascertain chip positions for the detecting step .

12. A method in accordance with claim 8 wherein in step (d) one line scan in each pair of line scans operated upon is subtracted from the other line scan in the same pair in order to reduce the effect of the video signal on, and to increase the amplitude of, the detected line of chips.

13. A method in accordance with claim 8 wherein each line scan is operated upon by deriving an integration function for each chip, and each chip function for one line scan is subtracted from a chip function for a correspondingly positioned chip in the paired line scan.

14. A method in accordance with claim 8 further including the steps of embedding a synchronizing chip pattern in a number of line scans of said video signal prior to its transmission, and operating on the received video signal to determine the position of the synchronizing chip pattern in order to ascertain chip positions for the detecting step.