Method and system for enhanced modulation of video signals

• US 20050195327A1
• Filed: 03/31/2005
• Published: 09/08/2005
• 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
• Granted Patent: US 7,586,541 B2
• Time in Patent Office: Days
• 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

1-22. -22. (canceled)

26. (canceled)

27. (canceled)

28. A method for detecting a carrier signal in a video signal, the video signal having one or more fields, each field having a plurality of scan lines, each scan line having a plurality of pixels, the method comprising:

obtaining the video signal;

reading the plurality of scan lines of the video signal into a signal matrix, the signal matrix having a plurality of rows that correspond to the plurality of scan lines, the plurality of rows each 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 each field;

adding each of the plurality of difference values to a line accumulator when each of the plurality of difference values is below a threshold value for each of the plurality of rows;

incrementing an in-range line count for each of the plurality of rows when the line accumulator is within a range for the plurality of fields; and

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

29. A method for detecting a carrier signal in a video signal for an interval, the video signal having one or more frames, each frame having a first field and a second field, the first field and the second field each having a plurality of scan lines, each scan line having a plurality of pixels, the method comprising:

obtaining the video signal;

reading the plurality of scan lines of each field of the video signal into a signal matrix;

calculating an optimum amount of adjustment for the first field and the second field of each frame of the video signal;

accumulating an encoded field value for each frame of the video signal that has been modulated; and

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

30. The method of claim 29, wherein calculating an optimum amount of adjustment 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 the plurality of pixels of the first field, each signal hiding position having a signal hiding value indicating a maximum amount of intensity that may be added to or subtracted from each of the corresponding plurality of pixels of the first;

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, each signal limiting position having a signal limiting value indicating a ceiling on the amount of intensity that may be added to or subtracted from each of the corresponding plurality of pixels of the first field; and

generating a real encoding value matrix by selecting for each of a plurality of real encoding value positions the corresponding signal hiding value from each of the plurality of signal hiding positions subject to the ceiling of the corresponding signal limiting value from each of the plurality of signal limiting positions.

31. A method for defeating the presence of a carrier signal in a modulated video signal, the modulated video signal having one or more frames, each frame having a plurality of scan lines, each scan line having a plurality of pixels, the method comprising:

obtaining the modulated video signal from a broadcast source; and

negating the presence of the carrier signal in the modulated video signal by means of a circumvention step.

50. The method of claim 31, wherein the means of a circumvention step comprises determining on the detection device a plurality of alterations to the plurality of pixels of the modulated video signal and altering the plurality of pixels of the modulated video signal by adding to the modulated video signal an inverse of the plurality of alterations.

51. The method of claim 31, wherein the means of a circumvention step comprises rotating each of the one or more frames of the modulated video signal.

52. The method of claim 31, wherein the means of a circumvention step comprises selectively rotating the one or more frames of the modulated video signal.

53. The method of claim 31, wherein the means of a circumvention step comprises raising the noise level in a second field of each of the one or more frames of the modulated video signal.

54. The method of claim 31, wherein the means of a circumvention step comprises selectively raising a noise level in one or more second fields of the one or more frames of the modulated video signal.

32-42. -42. (canceled)

43. A method for determining signal presence of a carrier signal in a plurality of fields of a video signal during an interval, the method comprising:

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

(ii) calculating a line accumulator by adding the 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 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;

(vii) subtracting the field accumulation to a signal strength indicator when the current field is not the first field; and

(viii) resetting the field accumulation, obtaining a next field of the plurality of fields of the video signal and repeating (ii-viii) when the interval is not complete.

23. The method of claim 43, wherein the interval is a predetermined number of fields.

24. The method of claim 43, wherein the interval is an adjustable number of fields based on an amount of accumulated energy.

25. The method of claim 43, wherein the interval is a defined amount of milliseconds.

44. The method of claim 43, 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.

45. The method of claim 43, further comprising providing a signal presence when the signal strength indicator is greater than a detection threshold.

46. The method of claim 43, further comprising providing a signal absence when the signal strength indicator is not greater than the detection threshold.

47. The method of claim 43, wherein obtaining a current field comprises reading a 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.

48. The method of claim 47, wherein calculating a 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 a 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.

49. The method of claim 48, further comprising verifying that the difference value is a proper value.