System and method for object based parametric video coding

• US 8,848,802 B2
• Filed: 09/04/2009
• Issued: 09/30/2014
• Est. Priority Date: 09/04/2009
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Inventors: Chaudhury, Santanu, Mathur, Mona, Khandelia, Aditya, Tripathi, Subarna, Lall, Brejesh, Roy, Sumantra Dutta, Gorecha, Saurabh
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): CHAU, PETER P
• Application Number:
  US12/554,579
• Publication Number:
  US 20110058609A1
• Time in Patent Office: 1,852 Days
• Field of Search: None
• US Class Current: 375/240.25
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 7/215 Motion-based segmentation
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/20 using video object coding
• CPC Class Codes: H04N 19/23 with coding of regions that are present throughout a whole video segment, e.g. sprites, background or mosaic
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/543 using regions
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

A video compression framework based on parametric object and background compression is proposed. At the encoder, an embodiment detects objects and segments frames into regions corresponding to the foreground object and the background. The object and the background are individually encoded using separate parametric coding techniques. While the object is encoded using the projection coefficients to the orthonormal basis of the learnt subspace (used for appearance based object tracking), the background is characterized using an auto-regressive (AR) process model. An advantage of the proposed schemes is that the decoder structure allows for simultaneous reconstruction of object and background, thus making it amenable to the new multi-thread/multi-processor architectures.

Claims

1. A digital video decoder, comprising:

a decoding block configured to decode background I frames and edge blocks of background P-frames in an encoded video sequence;

an object appearance estimator configured to estimate an object appearance based on object appearance parameters in the encoded video sequence;

a texture synthesizer coupled to the decoding block and configured to generate background P blocks based on auto regressive coefficients and thread information in the encoded video sequence and the decoded edge blocks; and

a frame compositor coupled to the decoding block, the object appearance estimator and the texture synthesizer and configured to generate a composite output frame based on outputs of the decoding block, the texture synthesizer and the object appearance estimator.

2. The decoder of claim 1, further comprising:

an object correction module configured to modify the estimated object appearance based on object residual information in the encoded video sequence.

3. The decoder of claim 2, further comprising:

an object motion compensator configured to compensate for object motion based on object motion parameters in the encoded video sequence.

4. The decoder of claim 1, further comprising:

a demultiplexer configured to split the encoded video sequence into;

encoded H.264 information;

AR (Auto-Regressive) coefficients and thread information; and

object appearance and motion parameters and compressed object residue information.

5. The decoder of claim 1 wherein when an error criteria is satisfied, the texture synthesizer is configured to output a previous background P block as a current background P block.

6. A method of decoding an encoded digital video sequence, the method comprising:

decoding background I frames in the encoded video sequence;

H.264/AVC (Advanced Video Coding) decoding edge blocks of background P frames;

estimating an object appearance based on object appearance parameters in the encoded video sequence;

generating background P frames based on auto regressive coefficients and thread information in the encoded video sequence and on the decoded edge block; and

generating a composite output frame based on the decoded background I frames, the estimated object appearance and the generated background P frames.

7. The method of claim 6 wherein estimating the object appearance includes:

modifying the estimated object appearance based on object residual information in the encoded video sequence.

8. The method of claim 7 wherein estimating the object appearance includes:

compensating for object motion based on object motion parameters in the encoded video sequence.

9. The method of claim 6, further comprising:

demultiplexing the encoded video sequence into;

encoded H.264/AVC (Advanced Video Coding) information;

AR (Auto-Regressive) coefficients and thread information; and

object appearance and motion parameters and compressed object residue information.

10. The method of claim 6 wherein, when an error criteria is satisfied, generating a background P frame comprises outputting a previous background P block as a current background P block.

11. A non-transitory computer-readable memory medium whose contents cause a processor to perform a method of decoding an encoded video image sequence, the method comprising:

decoding background I frames in the encoded video sequence;

H.264/AVC (Advanced Video Coding) decoding edge blocks of background P frames;

estimating an object appearance based on object appearance parameters in the encoded video sequence;

generating background P frames based on auto regressive coefficients and thread information in the encoded video sequence and on the decoded edge block; and

generating a composite output frame based on the decoded background I frames, the estimated object appearance and the generated background P frames.

12. The non-transitory computer-readable memory medium of claim 11 wherein the method further comprises:

modifying the estimated object appearance based on object residual information in the encoded video sequence.

13. The non-transitory computer-readable memory medium of claim 11 wherein the method further comprises:

compensating for object motion based on object motion parameters in the encoded video sequence.

14. The non-transitory computer-readable memory medium of claim 11 wherein the method further comprises:

demultiplexing the encoded video sequence into;

encoded H.264/AVC (Advanced Video Coding) information;

AR (Auto-Regressive) coefficients and thread information; and

object appearance and motion parameters and compressed object residue information.

15. The non-transitory computer-readable memory medium of claim 11 wherein the method further comprises:

when an error criteria is satisfied, outputting a previous background P block as a current background P block.

16. A system comprising:

a decoder comprising;

an H.264 I slice decoder configured to decode background I frames in an encoded video sequence;

an H.264 P slice decoder configured to decode edge blocks of background P frames;

an object appearance estimator configured to estimate an object appearance based on object appearance parameters in the encoded video sequence;

a texture synthesizer configured to generate background P frames based on auto regressive coefficients and thread information in the encoded video sequence and the decoded edge blocks of background P frames; and

a frame compositor coupled to the H.264 I slice decoder, the object appearance estimator and the texture synthesizer and configured to generate a composite output frame based on outputs of the H.264 I slice decoder, the texture synthesizer and the object appearance estimator; and

a digital video encoder.

17. The system of claim 16, further comprising:

an object correction module configured to modify the estimated object appearance based on object residual information in the encoded video sequence.

18. The system of claim 17, further comprising:

an object motion compensator configured to compensate for object motion based on object motion parameters in the encoded video sequence.

19. The system of claim 16, further comprising:

a demultiplexer configured to split the encoded video sequence into;

encoded H.264/AVC (Advanced Video Coding) information;

AR (Auto-Regressive) coefficients and thread information; and

object appearance and motion parameters and compressed object residue information.

20. The system of claim 16 wherein the texture synthesizer is configured to, when an error criteria is satisfied, output a previous background P block as a current background P block.

21. A system comprising:

a decoder comprising;

a decoding block configured to decode background I frames in an encoded video sequence;

an object appearance estimator configured to estimate an object appearance based on object appearance parameters in the encoded video sequence;

a texture synthesizer configured to generate background P frames based on auto regressive coefficients and thread information in the encoded video sequence; and

a frame compositor coupled to the decoding block, the object appearance estimator and the texture synthesizer and configured to generate a composite output frame based on outputs of the decoding block, the texture synthesizer and the object appearance estimator; and

a digital video encoder configured to;

segment frames in a digital video sequence into object regions and background regions;

generate object motion and appearance parameters based on segmented object regions; and

generate an auto regressive background model based on segmented background regions.