Method and system for enhanced modulation of video signals

• US 7,586,541 B2
• Filed: 03/31/2005
• Issued: 09/08/2009
• Est. Priority Date: 08/26/2003
• Status: Active Grant

• Current Assignee: Advocado, Inc.
• Original Assignee: Koplar Interactive Systems International, LLC
• Inventors: Chupp, Christopher E., Barsoum, Yousri H., Gramelspacher, Michael S., Withers, James G., Reynolds, Michael C., Chounard, Jesse J. II
• Primary Examiner(s): Natnael; Paulos M
• Application Number:
  US11/095,334
• Publication Number:
  US 20050195327A1
• Time in Patent Office: 1,622 Days
• Field of Search: 348/473, 348/469, 348/478, 348/476, 348/553, 348/564, 348/460, 348/461, 348/465, 380/203
• US Class Current: 348/473
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/85 using pre-processing or post-processing specially adapted for video compression
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 7/007 Systems with supplementary picture signal insertion during a portion of the active part of a television signal, e.g. during top and bottom lines in a HDTV letter-box system
• 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 7/08 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
• CPC Class Codes: H04N 7/081 the additional information signals being transmitted by means of a subcarrier

Abstract

A method for encoding a carrier signal in a video signal, the video signal having one or more frames, the frames each having a first field and a second field, the first field and the second field of each frame having a plurality of scan lines, each having a plurality of pixels with an intensity value indicating brightness, the method comprising selectively designating the plurality of scan lines of the first field of the one or more frames as up lines or down lines, calculating an optimum amount of adjustment to the pixels of the up lines and the down lines, and selectively increasing the intensity value of pixels of the up lines and decreasing the intensity value of pixels of the down lines by the optimum amount of adjustment thereby modulating the video signal with a carrier signal and creating a modulated video signal.

Claims

1. A method comprising:

reading a plurality of scan lines of a selected portion of a video signal into a signal matrix, the signal matrix having a plurality of rows that correspond to the plurality of scan lines, a row of the plurality of rows having a plurality of positions that correspond to the plurality of pixels;

obtaining a plurality of difference values by subtracting each of the plurality of positions on the plurality of rows with a corresponding plurality of positions in a subsequent row of the selected portion;

adding a difference value of the plurality of difference values to a line accumulator when the difference value is below a threshold value associated with the row;

incrementing an in-range line count for the row when the line accumulator is within a range for the selected portion; and

outputting a carrier absence for the selected portion when the in-range line count is less than or equal to an in-range threshold or a carrier presence for the selected portion when the in-range line count is greater than the in-range threshold.

2. The method of claim 1, wherein the selected portion is a frame or a field of the video signal.

3. A method comprising:

reading a plurality of scan lines of a first field and a second field of a frame into a signal matrix;

calculating an adjustment potential for the first field of the frame to select a potential encode area;

comparing the potential encoded area of the first field with the potential encode area of the second field to determine whether the frame has been modulated;

accumulating an encoded field value when the frame has been modulated; and

outputting a carrier absence for the frame when the encoded field value is less than or equal to a threshold value or a carrier presence for the frame when the encoded field value is greater than the threshold value.

4. The method of claim 3, wherein the calculating of the adjustment potential comprises:

generating a three dimensional signal hiding matrix;

transforming the three dimensional signal hiding matrix into a two dimensional signal hiding matrix, the two dimensional signal hiding matrix having a plurality of signal hiding positions that correspond to a plurality of pixels of the first field, a signal hiding position of the plurality of signal hiding positions having a signal hiding value indicating a maximum potential amount of intensity that may be added to or subtracted from a corresponding pixel of the first field;

generating a three dimensional signal limiting matrix;

transforming the three dimensional signal limiting matrix into a two dimensional signal limiting matrix, the two dimensional signal limiting matrix having a plurality of signal limiting positions that correspond to the plurality of pixels of the first field, a signal limiting position of the plurality of signal limiting positions having a signal limiting value indicating a ceiling on a potential amount of intensity that may be added to or subtracted from a corresponding pixel of the first field; and

generating a real encoding value matrix by selecting for a plurality of real encoding value positions a corresponding signal hiding value from the plurality of signal hiding positions subject to the ceiling of a corresponding signal limiting value from the plurality of signal limiting positions, the real encoding value matrix capable of being used as the potential encoded area.

5. A method comprising:

accessing a modulated video signal including a video carrier signal, the video carrier signal subliminally modulated within an active video portion of the modulated video signal; and

altering at least one frame of the modulated video signal in accordance with a circumvention technique to create an altered video signal,

wherein detectability of the presence of the video carrier signal in the modulated video signal is negated by the altering.

6. The method of claim 5, wherein the altering of the at least one frame comprises:

determining on a detection device a plurality of alterations to at least one frame, the plurality of alternations corresponding to a plurality of pixels of the frame, a particular alteration including an alteration value associated with an intensity adjustment to a particular pixel of the plurality of pixels; and

altering at least some of the plurality of pixels of the frame by adding a plurality of inverse alternation values, a particular pixel of the plurality of pixels altered by a particular inverse alteration value in an amount that is inverse to the intensity adjustment.

7. The method of claim 5, wherein the altering of the at least one frame comprises:

rotating the at least one frame of the modulated video signal.

8. The method of claim 7, wherein the at least one frame is rotated around a Z-axis.

9. The method of claim 7, wherein at least some of the plurality of pixels are misaligned in the at least one frame based on the rotating of the at least one frame.

10. The method of claim 7, wherein at least some of a plurality of scan lines of the at least one frame are misaligned based on the rotating of the at least one frame.

11. The method of claim 5, wherein the altering of the at least one frame comprises:

raising a noise level in a field of the at least one frame of the modulated video signal.

12. A method comprising:

(i) obtaining a current field of a plurality of fields of a video signal;

(ii) calculating a line accumulator by adding a difference of a plurality of pixels of a current scan line of the current field from the plurality of pixels of a previous scan line of the current field;

(iii) adding an absolute value of the line accumulator to a field accumulation;

(iv) resetting the line accumulator, advancing the current scan line to a next scan line in the current field and repeating (ii-iv) when the current field has the next scan line;

(v) adding the field accumulation to a signal strength indicator when the current field is a first field of a frame of the video signal;

(vii) subtracting the field accumulation from a signal strength indicator when the current field is not the first field of the frame of the video signal;

(viii) resetting the field accumulation, obtaining a next field of the plurality of fields of the video signal and repeating (ii-viii) until the plurality of fields is complete;

(ix) providing a signal presence for the plurality of fields when the signal strength indicator is greater than a detection threshold; and

(x) providing a signal absence for the plurality of fields when the signal strength indicator is not greater than the detection threshold.

13. The method of claim 12, further comprising:

setting a current scan line to a second viewable scan line in the current field and a previous scan line to a first viewable scan line in the current field.

14. The method of claim 12, wherein the obtaining of the current field comprises:

reading the current field of the video signal into a signal matrix, wherein the signal matrix has a plurality of positions that correspond to a plurality of pixels of the current field.

15. The method of claim 14, wherein the calculating of the line accumulator comprises:

(a) setting a position of a current line pointer to a first pixel of a first line of the signal matrix;

(b) setting the previous line pointer to the position of the current line pointer;

(c) setting the current line pointer to the position to the first pixel of a next line of the signal matrix;

(d) obtaining a difference value by subtracting an intensity value from the position of the previous line pointer from the position of the current line pointer;

(e) adding the difference value to the line accumulator; and

(f) advancing the previous line pointer and the current line pointer to a next pixel and repeating (b)-(f) until the end of a row of the signal matrix.

16. The method of claim 15, further comprising:

verifying that the difference value is a proper value;

wherein the difference value is added to the line accumulator when the difference value is the proper value.