Method and apparatus for encoding/decoding multi-layer video using DCT upsampling

• US 20060120448A1
• Filed: 11/29/2005
• Published: 06/08/2006
• Est. Priority Date: 12/03/2004
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ha, Ho-jin, Cha, Sang-chang, Han, Woo-jin
• Application Number:
  US11/288,210
• Publication Number:
  US 20060120448A1
• Time in Patent Office: Days
• US Class Current: 375/240.200
• CPC Class Codes: H04N 19/31 in the temporal domain
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/59 involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

A method and apparatus for more efficiently upsampling a base layer to perform interlayer prediction during multi-layer video coding are provided. The method includes encoding and reconstructing a base layer frame, performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed frame corresponding to a first block in an enhancement layer frame, calculating a difference between the first block and a third block generated by the DCT upsampling, and encoding the difference.

Claims

1. A method for encoding a multi-layer video comprising:

encoding and reconstructing a base layer frame;

performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed frame corresponding to a first block in an enhancement layer frame;

calculating a difference between the first block and a third block generated by the performing of the DCT upsampling; and

encoding the difference.

2. The method of claim 1, wherein the predetermined size is equal to a transform size of DCT in the base layer frame.

3. The method of claim 1, wherein the size is equal to the size of a motion block used in motion estimation on the base layer frame

4. The method of claim 1, wherein the performing of the DCT upsampling comprises:

performing DCT on the second block according to a transform size equal to a size of the second block;

adding zero padding to a fourth block consisting of DCT coefficients created as a result of the DCT and generating the third block having a size which is enlarged by a ratio of a resolution of an enhancement layer to a resolution of a base layer; and

performing inverse DCT on the third block according to a transform size equal to the size of the third block.

5. The method of claim 1, wherein a DCT downsampler is used to perform downsampling before the encoding of the base layer frame.

6. The method of claim 1, wherein the encoding of the difference comprises:

performing DCT of predetermined transform size on the difference to create DCT coefficients;

quantizing the DCT coefficients to produce quantization coefficients; and

performing lossless encoding on the quantization coefficients.

7. A method for encoding a multi-layer video comprising:

reconstructing a base layer residual frame from an encoded base layer frame;

performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed base layer residual frame corresponding to a first residual block in an enhancement layer residual frame;

calculating a difference between the first residual block and a third block generated by the DCT upsampling; and

encoding the difference.

8. The method of claim 7, wherein the predetermined size is equal to a transform size of DCT in the base layer frame.

9. The method of claim 7, wherein the performing of the DCT upsampling comprises:

performing DCT on the second block according to a transform size equal to a size of the second block;

adding zero padding to a fourth block consisting of DCT coefficients created as a result of the DCT and generating the third block having a size which is enlarged by a ratio of a resolution of an enhancement layer to a resolution of a base layer; and

performing inverse DCT on the third block according to a transform size equal to the size of the third block.

10. The method of claim 7, wherein the encoding of the difference comprises:

performing DCT of predetermined transform size on the difference to create DCT coefficients;

quantizing the DCT coefficients to produce quantization coefficients; and

performing lossless encoding on the quantization coefficients.

11. A method for encoding a multi-layer video comprising:

encoding and inversely quantizing a base layer frame;

performing discrete cosine transform (DCT) upsampling on a second block in the inversely quantized frame corresponding to a first block in an enhancement layer frame;

calculating a difference between the first block and a third block generated by the DCT upsampling; and

encoding the difference.

12. The method of claim 11, wherein the performing of the DCT upsampling comprises:

performing DCT on the second block according to a transform size equal to a size of the second block;

adding zero padding to a fourth block consisting of DCT coefficients created as a result of the DCT and generating the third block having a size which is enlarged by a ratio of a resolution of an enhancement layer to a resolution of a base layer; and

performing inverse DCT on the third block according to a transform size equal to the size of the third block.

13. The method of claim 11, wherein the encoding of the difference comprises:

performing DCT of predetermined transform size on the difference to create DCT coefficients;

quantizing the DCT coefficients to produce quantization coefficients; and

performing lossless encoding on the quantization coefficients.

14. A method for decoding a multi-layer video comprising:

reconstructing a base layer frame from a base layer bitstream;

reconstructing a difference frame from an enhancement layer bitstream;

performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed base layer frame corresponding to a first block in the difference frame; and

adding a third block generated by the DCT upsampling to the first block.

15. A method for decoding a multi-layer video comprising:

reconstructing a base layer frame from a base layer bitstream;

reconstructing a difference frame from an enhancement layer bitstream;

performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed base layer frame corresponding to a first block in the difference frame;

adding a third block generated by the DCT upsampling to the first block; and

adding a fourth block generated by adding the third block to the first block to a block in a motion-compensated frame corresponding to the fourth block.

16. A method for decoding a multi-layer video comprising:

extracting texture data from a base layer bitstream and inversely quantizing the extracted texture data;

reconstructing a difference frame from an enhancement layer bitstream;

performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the inversely quantized result corresponding to a first block in the difference frame; and

adding a third block generated by the DCT upsampling to the first block.

17. A multi-layered video encoder comprising:

means for encoding and reconstructing a base layer frame;

means for performing discrete cosine transform (DCT) upsampling on a

second block of a predetermined size in the reconstructed frame corresponding to a first block in an enhancement layer frame;

means for calculating a difference between the first block and a third block generated by the DCT upsampling; and

means for encoding the difference.

18. A multi-layered video decoder comprising:

means for reconstructing a base layer frame from a base layer bitstream;

means for reconstructing a difference frame from an enhancement layer bitstream;

means for performing discrete cosine transform (DCT) upsampling on a second block of a predetermined size in the reconstructed base layer frame corresponding to a first block in the difference frame; and

means for adding a third block generated by the DCT upsampling to the first block.