Method for coding and decoding moving image

• US 20060088224A1
• Filed: 10/25/2005
• Published: 04/27/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Jin Soo
• Granted Patent: US 7,936,824 B2
• Time in Patent Office: Days
• US Class Current: 382/240
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• CPC Class Codes: H04N 19/62 by frequency transforming in three dimensions H04N19/63 takes precedence

Abstract

Provided is a method of coding and decoding a moving image, which can optimize the coding rate and reduce the time required for decoding the first image frame during an operation of displaying the image. The coding method includes receiving an image, determining the number of frames in a GOP to be decoded with respect to the image, performing a 3D wavelet transformation on the GOP, and coding the results of the 3D wavelet transformation.

Claims

1. A method of coding a moving image, comprising:

receiving an image;

determining the number of frames in a GOP (group of picture) to be decoded with respect to the image;

performing a 3D (three-dimensional) wavelet transformation on the GOP; and

coding the results of the 3D wavelet transformation.

2. The method according to claim 1, wherein the determining of the number of the frames includes:

obtaining a difference between a previous image frame and a current image frame;

comparing the difference with a predetermined threshold value; and

determining image frames up to the current image frame as one GOP when the difference exceeds the predetermined threshold value.

3. The method according to claim 1, wherein the number of the frames is determined using a difference between a previous image frame and a current image frame and an accumulation value of the difference.

4. The method according to claim 3, wherein even if the difference does not exceed the predetermined threshold value, if the accumulation value exceeds a given threshold value, all image frames up to the latest image frame not causing the given threshold value to be exceeded are determined as one GOP.

5. The method according to claim 2, wherein the difference is calculated with respect to a Y component of the image.

6. The method according to claim 1, wherein the coding of the 3D wavelet transformation result includes:

dividing the 3D wavelet transformation results by a quantization parameter; and

compressing coefficients comprising the resulting quotients by a VLC (variable length coding) scheme.

7. The method according to claim 1, wherein the determining of the number of the frames is performed on each GOP to be coded.

8. A method of decoding an image, comprising:

receiving a coded image;

performing a VLD (variable length decoding) operation on the coded image;

performing an inverse quantization operation on the result of the VLD operation by a quantization parameter to extract data about the number of frames in a GOP (group of picture); and

performing a 3D (three dimensional) wavelet transformation on the inverse quantization result with reference to the number of the frames.

9. The method according to claim 8, wherein the number of the frames is determined by comparison of a difference between a previous image frame and a current image frame with a predetermined threshold value.

10. The method according to claim 8, wherein the number of the frames is determined with reference to a difference between a previous image frame and a current image frame and an accumulation value of the difference.

11. The method according to claim 9, wherein the difference is calculated using a Y component of the image.

12. The method according to claim 8, wherein the extracting of the number of the frames is performed on each GOP to be decoded.

13. An apparatus for decoding an image, comprising:

a VLD (variable length decoding) unit for performing a VLD operation on an inputted image;

a frame number extractor for performing an inverse quantization operation on the result of the VLD operation to extract data about the number of frames in a GOP (group of picture); and

a wavelet transformer for performing a wavelet transformation on the result of the inverse quantization.

14. The apparatus according to claim 13, wherein the number of the frames is determined by comparison of a difference between a previous image frame and a current image frame with a predetermined threshold value.

15. The apparatus according to claim 13, wherein the number of the frames is determined with reference to a difference between a previous image frame and a current image frame and an accumulation value of the difference.

16. The apparatus according to claim 14, wherein the difference is calculated using a Y component of the image.

17. The apparatus according to claim 13, wherein the extracting of the number of the frames is performed on each of GOPs to be decoded.