Video Watermarking Using Temporal Analysis

• US 20080226120A1
• Filed: 10/30/2007
• Published: 09/18/2008
• Est. Priority Date: 07/24/1997
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Zhu, Bin, Tewfik, Ahmed, Swanson, Mitch
• Granted Patent: US 8,155,375 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/0085 Time domain based watermarking, e.g. watermarks spread over several images
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0081 whereby both original and watermarked images are required at decoder, e.g. destination-based, non-blind, non-oblivious
• CPC Class Codes: G06T 2201/0202 whereby the quality of watermarked images is measured; Measuring quality or performance of watermarking methods; Balancing between quality and robustness
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/467 characterised by the embedded information being invisible, e.g. watermarking
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/619 the transform being operated outside the prediction loop
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 2005/91335 the copy protection signal being a watermark
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 5/782 on tape
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection

Abstract

Methods of embedding and detecting watermarks in video use temporal analysis to compute temporal components of video from which the watermarks are embedded and detected. Temporal analysis, such as a temporal wavelet, is used to compute representations of static and dynamic portions of the video. For embedding, watermarks are computed from and/or adapted to the temporal components. For detecting, temporal properties are exploited to detect watermarks in the static and/or dynamic components. Temporal analysis also enables plural watermarks to be embedded at different levels of temporal resolution.

Claims

1. A method of embedding data in video, the method comprising:

performing a temporal analysis of video to produce temporal components of the video;

providing watermark data;

adapting the watermark data to the temporal components; and

embedding the adapted watermark signal into the video signal.

2. The method of claim 1 wherein the embedding comprises:

embedding the watermark data in the temporal components to produce watermarked temporal components.

3. The method of claim 2 wherein the temporal analysis comprises a temporal wavelet transform.

4. The method of claim 1 wherein the temporal components include a video components at plural different temporal scales.

5. The method of claim 1 wherein the temporal components represent changes in the video over time, the watermark data being embedded in the temporal components representing changes in the video over time.

6. The method of claim 1 wherein a first of the temporal components represents local changes in video while a second of the temporal component represents video features that remain relatively unchanged over time.

7. A method of embedding data in video, the method comprising:

transforming video into plural levels of temporal resolution;

providing watermark signals for separately embedding data in the plural levels of temporal resolution;

adapting the watermark signals to corresponding video at the plural levels of temporal resolution; and

embedding the adapted watermark signals in the corresponding video at the plural levels of temporal resolution.

8. A method of detecting data embedded in video, the method comprising:

receiving video frames with data embedded into a temporal domain representation of the video frames, the temporal domain representation comprising changes of the video signal in the video frame over time;

extracting a temporal component from plural of the video frames corresponding to the temporal domain representation; and

detecting a watermark in the temporal component.

9. The method of claim 8 including combining video frames and using the combined video frames to detect a first watermark at a low temporal resolution.

10. A method of detecting data embedded in video, the method comprising:

receiving video frames with data embedded into video signals of the video frames that is computed from a temporal analysis of the video signals;

combining the video frames to compute a temporal component of the video frames; and

detecting a watermark in the temporal component.