VIDEO ENCODING METHOD AND APPARATUS AND VIDEO DECODING METHOD AND APPARATUS USING RESIDUAL RESIZING

• US 20080192825A1
• Filed: 12/21/2007
• Published: 08/14/2008
• Est. Priority Date: 02/14/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Han, Woo-Jin, Lee, Tammy
• Granted Patent: US 8,300,691 B2
• Time in Patent Office: Days
• US Class Current: 375/240.12
• 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 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/48 using compressed domain processing techniques other than decoding, e.g. modification of transform coefficients, variable length coding [VLC] data or run-length data motion estimation in a transform domain H04N19/547; processing of decoded motion vectors H04N19/513
• CPC Class Codes: H04N 19/50 using predictive coding H04N19/61 takes precedence
• 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 19/59 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
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop

Abstract

A video encoding method and apparatus and a video decoding method and apparatus are provided. The video encoding method encodes residual values included in a residual block of a current block after sub-sampling or down-sampling the residual values, thereby encoding and decoding the current block using a small number of residual values and thus improving the compression rate of video encoding.

Claims

1. A video encoding method comprising:

generating a prediction block of a current block and subtracting the generated prediction block from the current block in order to produce a residual block of the current block;

sub-sampling residual values for a plurality of pixels included in the residual block in order to select first residual values to be encoded from among the residual values; and

encoding the first residual values.

2. The video encoding method of claim 1, wherein the first residual values are included in at least one of even rows and even columns of the current block.

3. The video encoding method of claim 1, wherein the first residual values are included in at least one of odd rows and odd columns of the current block.

4. The video encoding method of claim 1, wherein the first residual values are selected based on a gradient map of the prediction block.

5. The video encoding method of claim 1, wherein the selecting of the first residual values to be encoded comprises shifting the first residual values to a top portion and to a left portion of the current block, and the encoding of the first residual values comprises performing discrete cosine transformation (DCT) on the shifted first residual values.

25. A computer-readable recording medium having recorded thereon a program for executing the video encoding method of claim 1.

6. A video encoding method comprising:

generating a prediction block of a current block and subtracting the generated prediction block from the current block in order to produce a residual block of the current block;

down-sampling residual values for a plurality of pixels included in the residual block; and

encoding the down-sampled residual values.

7. A video encoding apparatus comprising:

a residue generation unit which generates a prediction block of a current block and which subtracts the generated prediction block from the current block in order to produce a residual block of the current block;

a sampling unit which sub-samples residual values for a plurality of pixels included in the residual block in order to select first residual values to be encoded from among the residual values; and

an encoding unit which encodes the first residual values.

8. The video encoding apparatus of claim 7, wherein the first residual values are included in at least one of even rows and even columns of the current block.

9. The video encoding apparatus of claim 7, wherein the first residual values are included in at least one of odd rows and odd columns of the current block.

10. The video encoding apparatus of claim 7, wherein the first residual values are selected based on a gradient map of the prediction block.

11. The video encoding apparatus of claim 7, wherein the sampling unit sub-samples the residual values for a plurality of pixels included in the residual block in order to select first residual values to be encoded from among the residual values and shifts the first residual values to the top portion and to the left portion of the current block, and the encoding unit performs discrete cosine transformation (DCT) on the shifted first residual values.

12. A video encoding apparatus comprising:

a residue generation unit which generates a prediction block of a current block and which subtracts the generated prediction block from the current block in order to produce a residual block of the current block;

a sampling unit which down-samples residual values for a plurality of pixels included in the residual block; and

an encoding unit which encodes the down-sampled residual values.

13. A video decoding method comprising:

receiving a bitstream including data of a current block and extracting a residual block of the current block from the received bitstream;

wherein the residual block includes sub-sampled residual values;

reconstructing remaining residual values of the extracted residual block based on the sub-sampled residual values included in the extracted residual block; and

reconstructing the current block based on the sub-sampled residual values and the reconstructed residual values.

14. The video decoding method of claim 13, wherein the reconstructing of the remaining residual values comprises performing interpolation based on the sub-sampled residual values.

15. The video decoding method of claim 13, wherein the reconstructing of the remaining residual values comprises copying the sub-sampled residual values to other residual values that are adjacent to each of the sub-sampled residual values.

16. The video decoding method of claim 13, wherein the reconstructing of the remaining residual values comprises setting the remaining residual values except for the sub-sampled residual values to 0.

17. The video decoding method of claim 13, wherein the reconstructing of the remaining residual values comprises:

rearranging the sub-sampled residual values to the original position before sub-sampling; and

reconstructing the remaining residual values based on the rearranged residual values.

26. A computer-readable recording medium having recorded thereon a program for executing the video decoding method of claim 13.

18. A video decoding method comprising:

receiving a bitstream including data of a current block and extracting a residual block of the current block from the received bitstream;

wherein the residual block includes down-sampled residual values;

performing up-sampling based on down-sampled residual values included in the extracted residual block; and

reconstructing the current block based on the up-sampled residual values.

19. A video decoding apparatus comprising:

a decoding unit which receives a bitstream including data of a current block and which extracts a residual block of the current block from the received bitstream;

wherein the residual block includes sub-sampled residual values;

a residue reconstruction unit which reconstructs remaining residual values of the extracted residual block based on sub-sampled residual values included in the extracted residual block; and

a reconstruction unit which reconstructs the current block based on the sub-sampled residual values and the reconstructed residual values.

20. The video decoding apparatus of claim 19, wherein the residue reconstruction unit performs interpolation based on the sub-sampled residual values.

21. The video decoding apparatus of claim 19, wherein the residue reconstruction unit copies the sub-sampled residual values to other residual values that are adjacent to each of the sub-sampled residual values.

22. The video decoding apparatus of claim 19, wherein the residue reconstruction unit sets the remaining residual values except for the sub-sampled residual values to 0.

23. The video decoding apparatus of claim 19, wherein the residue reconstruction unit rearranges the sub-sampled residual values to the original position before sub-sampling and reconstructs the remaining residual values based on the rearranged residual values.

24. A video decoding apparatus comprising:

a decoding unit which receives a bitstream including data of a current block and which extracts a residual block of the current block from the received bitstream;

wherein the residual block includes down-sampled residual values;

a residue reconstruction unit which performs up-sampling based on down-sampled residual values included in the extracted residual block; and

a reconstruction unit which reconstructs the current block based on the up-sampled residual values.