Embedding data in and detecting embedded data from video objects

• US 20080219496A1
• Filed: 10/29/2007
• Published: 09/11/2008
• 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 8,090,142 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0071 using multiple or alternating watermarks
• 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: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• 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 19/17 the unit being an image region, e.g. an object
• 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 19/63 using sub-band based transform, e.g. wavelets
• 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 21/44008 involving operations for analysing video streams, e.g. detecting features or characteristics in the video stream arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• 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

Abstract

Methods for embedding data, such as digital watermarks, in video objects segmented from video frames. Watermarks are embedded such that they move with the object in the video frames. Interframe motion of video objects is estimated and used to modify the watermark accordingly. Methods for detecting embedded data from video objects are also disclosed.

Claims

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

receiving video frames including video objects, wherein at least one of the video objects is segmented from the video frames;

embedding data into the at least one video object; and

combining the video objects, including the at least one video object with embedded data, into video frames to produce a video stream including the at least one video object separately embedded with data.

2. The method of claim 1 wherein interframe motion of the segmented video object is estimated and used to modify the embedded data in different video frames.

3. The method of claim 1 wherein the at least one video object has corresponding motion parameters that define the motion of the video object relative to at least a first frame.

4. The method of claim 3 wherein the video object is segmented into blocks and the blocks have corresponding motion parameters.

5. The method of claim 1 including computing distortion associated with re-inserting a watermark for a video object from a previous frame into the video object for a current frame, and embedding the watermark from the previous frame into the video object for the current frame when the distortion is below a predetermined threshold.

6. The method of claim 1 wherein unique watermarks are embedded in different video objects segmented from the video frames.

7. The method of claim 1 including estimating interframe motion.

8. A method of embedding a watermark into video, the method comprising;

receiving video frames, including at least one video object that has been segmented from the video frames;

receiving motion parameters that define motion of the video object in the video frames;

embedding a watermark in the video object in plural frames, including using the motion parameters so that location of the watermark in the video frames corresponds to motion of the video object.

9. The method of claim 8 including computing the watermark as function of a frequency domain transform of the video object in the frames.

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

identifying at least one video object in the video frames, including motion parameters describing motion of the video object in the video frames;

providing a watermark key corresponding to a watermark embedded in the object;

using the watermark key to detect the watermark embedded in the video object.