Marking a video and/or audio signal
First Claim
1. A method of marking a video and/or audio signal which has at least two components, said components having values which are related according to a predetermined encoding standard;
- said method comprising the steps of;
identifying a region of said signal wherein a first of said components has a predetermined value; and
assigning to a second of said components a value in said region which, although in compliance with said standard, is nevertheless inconsistent with said predetermined value of the first of said components.
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Accused Products
Abstract
Method and arrangement for marking a video or audio signal to assign a classification to said signal, for example, to identify that the signal is authentic and may not be copied. The signal comprises at least two components (Y, UV) according to a predetermined standard (MPEG, PAL, NTSC). According to the invention, values are assigned to said components which in combination can normally not occur. For example, in black picture portions where Y, U and V are all zero, U and/or V are now wilfully made non-zero to constitute the watermark. Television receivers still display said black portion. The watermark is not lost when the signal is re-encoded and copied on a recordable disc. A player will not reproduce the copy because the watermark no longer corresponds with the "wobble key" of the new disc.
161 Citations
15 Claims
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1. A method of marking a video and/or audio signal which has at least two components, said components having values which are related according to a predetermined encoding standard;
- said method comprising the steps of;
identifying a region of said signal wherein a first of said components has a predetermined value; and assigning to a second of said components a value in said region which, although in compliance with said standard, is nevertheless inconsistent with said predetermined value of the first of said components. - View Dependent Claims (2, 3)
- said method comprising the steps of;
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4. A method of detecting whether a video signal which has at least two components is marked in accordance with a predetermined encoding standard relating to the relative values of said components;
- said method comprising the steps of;
determining whether there is a region of said video signal wherein a first of said components has a value of substantially zero; and determining whether all other components of said video signal have non-zero values in said region, and in that event providing an output signal signifying that the video signal is marked in accordance with said standard. - View Dependent Claims (5, 6)
- said method comprising the steps of;
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7. A device for marking a video and/audio signal which has at least two components, said components having values which are related in accordance with a predetermined encoding standard;
- comprising;
detecting means for identifying a region of said signal wherein a first of said components has a predetermined value; and mark generating means for assigning to a second of said components a value in said region which, although in compliance with said standard, is inconsistent with said predetermined value of said first component. - View Dependent Claims (8, 9)
- comprising;
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10. A device for detecting whether a video and/or audio input signal having at least two components is marked in accordance with a predetermined encoding standard relating to the values of said components;
- comprising;
first detecting means for receiving said input signal and deriving therefrom a first detection signal indicating whether there is a region of said input signal wherein a first of said components has a substantially zero value; second detecting means for also receiving said input signal and deriving therefrom a second detection signal signifying whether there is in said region a second component of said input signal having a non-zero value; and calculating means coupled to said first and second detection means and responsive to the detection signals produced thereby to produce a marking signal when said first component has a substantially zero value in said region and said second component has a non-zero value in said region. - View Dependent Claims (11, 12)
- comprising;
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13. A video and/or audio signal which is marked to indicate a classification thereof, said signal having at least two components the values of which are related according to a predetermined encoding standard;
- said signal having a region wherein a first of said components has a predetermined value and a second of said components has a value which, although in compliance with said standard, is nevertheless inconsistent with said predetermined value of the first component.
- View Dependent Claims (14, 15)
Specification