Methods and apparatus for error-resilient video coding

• US 6,661,842 B1
• Filed: 09/22/2000
• Issued: 12/09/2003
• Est. Priority Date: 09/22/2000
• Status: Expired due to Term

• Current Assignee: General Dynamics C4 Systems Incorporated (General Dynamics Corporation)
• Original Assignee: General Dynamics Decision Systems, Inc. (General Dynamics Corporation)
• Inventors: Abousleman, Glen Patrick
• Primary Examiner(s): Philippe, Gims S.
• Application Number:
  US09/667,903
• Time in Patent Office: 1,173 Days
• Field of Search: 375/240.11, 375/240.01, 375/240.16, 375/240.19, 375/240.21, 375/240.23, 382/233, 382/240, 382/244, 382/248, 348/398.1, 348/408.1, 348/699
• US Class Current: 375/240.11
• CPC Class Codes: H03M 13/41 using the Viterbi algorithm or Viterbi processors
• CPC Class Codes: H04N 19/10 using adaptive coding
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• CPC Class Codes: H04N 19/126 Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
• CPC Class Codes: H04N 19/146 Data rate or code amount at the encoder output
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/19 using optimisation based on Lagrange multipliers
• CPC Class Codes: H04N 19/503 involving temporal prediction adaptive coding with adaptive selection between spatial and temporal predictive coding H04N19/107; adaptive coding with adaptive selection among a plurality of temporal predictive coding modes H04N19/109
• 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 19/645 by grouping of coefficients into blocks after the transform

Abstract

Apparatus and methods are provided for encoding an input frame of a video sequence for transmission over a channel. The method and apparatus decompose the input frame into multiple subbands and divide the multiple subbands into multiple blocks corresponding to a region of the input frame. The blocks in the highest frequency subbands of the multiple blocks are selected based upon a luminance component of the input frame and the multiple blocks in the highest frequency subbands are classified into a multiple classes to provide a multiple class labels. The multiple class labels are collected to form a subband class map for each of the multiple blocks in the highest frequency subbands and a global class map is constructed from a majority evaluation of the subband map for each of the multiple blocks. The multiple blocks within the multiple subbands are grouped which have one of the class labels to form multiple subband class sequences.

Claims

1. A method of coding a input frame of a video sequence for transmission over a channel, comprising:

decomposing said input frame into a plurality of subbands;

dividing said plurality of subbands into a plurality of blocks corresponding to a region of said input frame;

selecting said plurality of blocks in a plurality of highest frequency subbands of said plurality of subbands based upon a luminance component of said input frame;

classifying said plurality of blocks in said plurality of highest frequency subbands into a plurality of classes to provide a plurality of class labels for said plurality of blocks in said plurality of highest frequency subbands;

collecting said plurality of class labels to form a subband classification map for each of said plurality of blocks in said plurality of highest frequency subbands;

constructing a global classification map from a majority evaluation of said subband classification map for each of said plurality of blocks in said plurality of highest frequency subbands; and

grouping said plurality of blocks within said plurality of subbands having one of said plurality of class labels to form a plurality of subband class sequences.

2. The method of claim 1, wherein said decomposing said input frame into a plurality of subbands is a two-dimensional discrete wavelet transform (DWT).

3. The method of claim 1, further comprising encoding said plurality of subband class sequences.

4. The method of claim 3, wherein said encoding is channel-optimized trellis coded quantization (COTCQ) encoding.

5. The method of claim 1, further comprising phase scrambling said plurality of subband class sequences.

6. The method of claim 1, further comprising normalizing said plurality of subband class sequences.

7. A apparatus for coding a input frame of a video sequence for transmission over a channel, comprising:

a decomposer configured to receive said input frame and decompose said input frame into a plurality of subbands that are divided into a plurality of blocks corresponding to a region of said input frame; and

a classifier configured to receive said plurality of subbands that are divided into said plurality of blocks corresponding to said region of said input frame, said classifier also configured to;

select said plurality of blocks in a plurality of highest frequency subbands of said plurality of subbands based upon a luminance component of said input frame;

classify said plurality of blocks in said plurality of highest frequency subbands into a plurality of classes to provide a plurality of class labels for said plurality of blocks in said plurality of highest frequency subbands;

collect said plurality of class labels to form a subband classification map for each of said plurality of blocks in said plurality of highest frequency subbands;

construct a global classification map from a majority evaluation of said subband classification map for each of said plurality of blocks in said plurality of highest frequency subbands; and

grouping said plurality of blocks within said plurality of subbands having one of said plurality of class labels to form a plurality of subband class sequences.

8. The apparatus of claim 7, wherein said decomposer is configured to decompose said frame into a plurality of subbands with a two-dimensional discrete wavelet transform (DWT).

9. The apparatus of claim 7, further comprising an encoder configured to encode said plurality of subband class sequences.

10. The apparatus of claim 9, wherein said encoder is configured to perform channel-optimized trellis coded quantization (COTCQ) encoding.

11. The apparatus of claim 7, further comprising a phase scrambler configured to phase scramble said plurality of subband class sequences.

12. The apparatus of claim 7, further comprising a normalizer configured to normalize said plurality of subband class sequences.

13. A method for coding a video sequence for transmission over a channel, comprising:

receiving the video sequence, the video sequence having a plurality of frames;

grouping said plurality of frames into a group of pictures;

coding an initial frame of said group of pictures to produce a coded initial frame;

transmitting said coded initial frame over the channel;

decoding said coded initial frame to produce a decoded initial frame;

constructing a first error frame estimate with said decoded initial frame;

obtaining a first error frame of a first frame from said first error frame estimate and said first frame;

coding said first error frame to produce a first coded error frame, said coding said first error frame comprising;

decomposing said first error frame into a plurality of subbands;

dividing said plurality of subbands into a plurality of blocks corresponding to a region of said first error frame;

selecting said plurality of blocks in a plurality of highest frequency subbands of said plurality of subbands based upon a luminance component of said first error frame;

classifying said plurality of blocks in said plurality of highest frequency subbands into a plurality of classes to provide a plurality of class labels for said plurality of blocks in said plurality of highest frequency subbands;

collecting said plurality of class labels to form a subband classification map for each of said plurality of blocks in said plurality of highest frequency subbands;

constructing a global classification map from a majority evaluation of said subband classification map for each of said plurality of blocks in said plurality of highest frequency subbands;

grouping said plurality of blocks within said plurality of subbands having one of said plurality of class labels to form a plurality of subband class sequences; and

encoding said plurality of subband class sequences to form said first coded error frame; and

transmitting said first coded error frame over the channel.

14. The method of claim 13, further comprising:

decoding said first coded error frame to produce a decoded first error frame;

constructing a second error frame estimate with said decoded first error frame;

obtaining a second error frame of a second frame from said second error frame estimate and said second frame;

coding said second error frame to produce a second coded error frame; and

transmitting said second coded error frame over the channel.

15. The method of claim 14, wherein coding said second error frame to produce a second coded error frame comprises:

decomposing said second error frame into a second plurality of subbands;

dividing said second plurality of subbands into a second plurality of blocks corresponding to a second region of said second error frame;

selecting said second plurality of blocks in a second plurality of highest frequency subbands of said second plurality of subbands based upon a second luminance component of said second error frame;

classifying said second plurality of blocks in said second plurality of highest frequency subbands into a second plurality of classes to provide a second plurality of class labels for said second plurality of blocks in said second plurality of highest frequency subbands;

collecting said second plurality of class labels to form a second subband classification map for each of said second plurality of blocks in said second plurality of highest frequency subbands;

constructing a second global class map from a second majority evaluation of said second subband classification map for each of said second plurality of blocks in said second plurality of highest frequency subbands;

grouping said second plurality of blocks within said second plurality of subbands having one of said second plurality of class labels to form a second plurality of subband class sequences; and

encoding said second plurality of subband class sequences to form said second coded error frame.

16. The method of claim 13, wherein said decomposing said first error frame into a plurality of subbands is a two-dimensional discrete wavelet transform (DWT).

17. The method of claim 13, further comprising encoding said plurality of subband class sequences.

18. The method of claim 17, wherein said encoding is channel-optimized trellis coded quantization (COTCQ) encoding.

19. The method of claim 13, further comprising phase scrambling said plurality of subband class sequences.

20. The method of claim 13, further comprising normalizing said plurality of subband class sequences.