Image coding method and apparatus and image decoding method and apparatus

• US 20030068090A1
• Filed: 07/23/2002
• Published: 04/10/2003
• Est. Priority Date: 07/26/2001
• Status: Active Grant

• Current Assignee: JBF Partners Incorporated
• Original Assignee: Monolith Company Limited
• Inventors: Akiyoshi, Nobuo, Akiyoshi, Kozo
• Granted Patent: US 7,212,572 B2
• Time in Patent Office: Days
• US Class Current: 382/240
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy
• CPC Class Codes: H04N 19/53 Multi-resolution motion estimation; Hierarchical motion estimation
• CPC Class Codes: H04N 19/54 using feature points or meshes
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures

Abstract

An image processing method and apparatus for encoding and decoding image data in which the coding and decoding method may be simplified based on factors such as processing speed requirements. In encoding, an image input unit receives a first image and a second image (key frames). A matching processor begins performing a multiresolutional analysis using pixel-by-pixel matching between the images but, due to predetermined factors or settings, either discontinues the analysis or switches to a simplified method of analysis prior to the final resolution level. If the analysis is discontinued during encoding (i.e. at the encoding side), the analysis may be completed at the decoding side prior to conducting the decoding and the decoding side may be arranged accordingly.

Claims

1. An image coding method, comprising:

preparing a multiresolutional image hierarchy;

conducting analysis on the multiresolutional image hierarchy; and

switching the analysis to a simplified method at a stage prior to a final stage.

2. An image coding method, comprising:

generating corresponding point data by analyzing a first image and a second image in a multiresolutional manner; and

outputting the corresponding point data generated by said generating,

wherein said generating is such that the analyzing comprises switching to a simplified method at a stage prior to reaching a final resolution of the first and second images.

3. An image coding method according to claim 2, wherein the simplified method comprises projecting corresponding point data of the first and second images at non-final resolution onto the first and second images at final resolution.

4. An image coding method according to claim 2, wherein corresponding point data that have been generated prior to switching to a simplified method are output on the assumption that the simplified method is to be executed at a decoding side.

5. An image coding method according to claim 2, further comprising:

compressing the first and second images respectively in an intra-frame format; and

outputting compressed data obtained by said compressing together with the corresponding point data.

21. An image coding method according to claim 2, wherein the simplified method comprises acquiring corresponding point data at a final resolution by performing block matching based on corresponding point data of the first and second images at a non-final resolution.

6. An image decoding method comprising decoding coded data that has been coded by analyzing images in a multiresolutional manner, the method characterized in that, if, during coding, the analyzing has been discontinued before reaching a final resolution stage, analyzing for remaining resolution stages is conducted at a decoding side using a simplified method.

7. An image decoding method, the method characterized in that:

during coding, corresponding point data between a first image and a second image have been generated by analyzing the first and second images in a multiresolutional manner but the analyzing has been discontinued at a stage prior to reaching final resolution of the first and second images; and

analyzing for remaining resolution stages is conducted at a decoding side using a simplified method so that completed coded data are available at the decoding side.

8. An image decoding method according to claim 7, wherein the simplified method comprises projecting corresponding point data of the first and second images at non-final resolution onto the first and second images at final resolution.

9. An image decoding method according to claim 8, further comprising generating an intermediate image of the first and second images based on the completed coded data and outputting the intermediate image.

22. An image decoding method according to claim 7, wherein the simplified method comprises acquiring corresponding point data at a final resolution by performing block matching based on corresponding point data of the first and second images at a non-final resolution.

10. An image coding apparatus for analyzing images in a multiresolutional manner, characterized in that, the analyzing is switched to a simplified method at a stage prior to a final resolution.

11. An image coding apparatus, comprising:

a matching processor which generates corresponding point data by analyzing a first image and a second image in a multiresolutional manner; and

a stream generator which outputs, as coded data, the corresponding point data generated by said matching processor,

wherein said matching processor switches the analyzing to a simplified method at a stage prior to reaching a final resolution of the first and second images.

12. An image coding apparatus according to claim 11, wherein the simplified method comprises projecting corresponding point data of the first and second images at non-final resolution onto the first and second images at final resolution.

13. An image coding apparatus according to claim 11, wherein corresponding point data that have been generated prior to switching to the simplified method are output on the assumption that the simplified method is to be executed at a decoding side.

14. An image coding apparatus according to claim 11, further comprising:

a key frame compressing unit which compresses the first and second images respectively in an intra-frame format,

wherein compressed data from said key frame compressing unit are output in a manner that the compressed data are incorporated into the coded data.

23. An image coding apparatus according to claim 11, wherein the simplified method comprises acquiring corresponding point data at a final resolution by performing block matching based on corresponding point data of the first and second images at a non-final resolution.

15. An image decoding apparatus for decoding coded data that has been coded by analyzing images in a multiresolutional manner, the apparatus characterized in that, if, during coding, the analyzing has been discontinued at a stage prior to a final resolution stage, analyzing for remaining resolution stages is conducted at a decoding side using a simplified method.

16. An image decoding apparatus, the apparatus characterized in that:

during coding, corresponding point data between a first image and a second image have been generated by analyzing the first and second images in a multiresolutional manner but the analyzing has been discontinued at a stage prior to reaching a final resolution of the first and second images; and

analyzing for remaining resolution stages is conducted at a decoding side using a simplified method so that completed coded data are available at the decoding side.

17. An image decoding apparatus according to claim 16, wherein the simplified method comprises projecting corresponding point data of the first and second images at non-final resolution onto the first and second images at final resolution.

18. An image decoding apparatus according to claim 17, further comprising an intermediate image generator which generates an intermediate image of the first and second images based on the completed coded data.

24. An image decoding apparatus according to claim 16, the simplified method comprises acquiring corresponding point data at a final resolution by performing block matching based on corresponding point data of the first and second images at a non-final resolution.

19. A computer program executable by a computer, the program comprising the functions of:

preparing a multiresolutional image;

conducting analysis on the multiresolutional image; and

switching the analysis to a simplified method at a stage prior to a final stage.

20. A computer program executable by a computer, for decoding data that has been coded by analyzing images in a multiresolutional manner, the program including the functions of determining if the analyzing has been discontinued at a stage prior to a final resolution stage and conducting analyzing for remaining resolution stages using a simplified method.