Claims
- 1. A coding apparatus for hierarchically coding an image, comprising:
- input means for entering, line by line, a plurality of consecutive lines of image data representing pixels of the image, the image having a first number of pixels each represented by respective image data;
- forming means for forming reduced image data representing pixels of a reduced image based on the image data entered by said input means, the reduced image data having a second number of pixels each represented by respective reduced image data, where the second number is smaller than the first number;
- determining means, which operates in parallel with the formation of the reduced image data by said forming means, for determining whether or not image data of an object pixel to be coded can be predicted from the reduced image data being formed by said forming means and from image data representing surrounding pixels of the object pixel entered by said input means; and
- coding means for coding the image data entered by said input means in accordance with a determination result of said determining means,
- wherein image data which has been determined to be predictable by said determining means is excluded from coding by said coding means so as not to have a respective code corresponding thereto.
- 2. The apparatus according to claim 1, wherein said determining means forms data representative of whether or not the image data can be predicted.
- 3. The apparatus according to claim 1, wherein said forming means forms the reduced image data based on the image data representing a plurality of pixels of the image and based on the reduced image data representing a plurality of pixels of the reduced image.
- 4. The apparatus according to claim 1, wherein said determining means determines whether or not image data of a plurality of pixels associated with a pixel represented by the reduced image data can be predicted.
- 5. The apparatus according to claim 1, wherein said coding means codes the image data which said determining means determines cannot be predicted.
- 6. The apparatus according to claim 5, wherein said coding means codes the image data by means of prediction coding based on the reduced image data formed by said forming means and based on the image data entered by said input means.
- 7. The apparatus according to claim 1, further comprising delay means for delaying the image data entered by said input means by a time required for a determination operation by said determining means.
- 8. A method for hierarchically coding an image, comprising:
- an input step of entering, line by line, a plurality of consecutive lines of image data representing pixels of the image, the image having a first number of pixels each represented by respective image data;
- a forming step of forming reduced image data representing pixels of a reduced image based on the image data entered by said input step, the reduced image data having a second number of pixels each represented by respective reduced image data, where the second number is smaller than the first number;
- a determining step, which is performed in parallel with the formation of the reduced image data in said forming step, of determining whether or not image data of an object pixel to be coded can be predicted from the reduced image data being formed in said forming step and from image data representing surrounding pixels of the object pixel entered in said input step; and
- a coding step of coding the image data entered in said input step in accordance with a determination result of said determining step,
- wherein in said coding step, image data which has been determined to be predictable in said determining step is excluded from coding so as not to have a respective code corresponding thereto.
- 9. The method according to claim 8, wherein said determining step forms data representative of whether or not the image data can be predicted.
- 10. The method according to claim 8, wherein said forming step forms the reduced image data based on the image data representing a plurality of pixels of the image and based on the reduced image data representing a plurality of pixels of the reduced image.
- 11. The method according to claim 8, wherein said determining step determines whether or not image data of a plurality of pixels associated with a pixel represented by the reduced image data can be predicted.
- 12. The method according to claim 8, wherein said coding step codes the image data which said determining step determines cannot be predicted.
- 13. The method according to claim 12, wherein said coding step codes the image data by means of prediction coding based on the reduced image data formed in said forming step and based on the image data entered in said input step.
- 14. The method according to claim 8, further comprising a delay step for delaying the image data entered in said input step by a time required for a determination operation in said determining step.
Priority Claims (3)
Number |
Date |
Country |
Kind |
4-221768 |
Aug 1992 |
JPX |
|
4-303934 |
Nov 1992 |
JPX |
|
4-331956 |
Dec 1992 |
JPX |
|
Parent Case Info
This application is a division of application Ser. No. 08/515,385 filed Aug. 15, 1995, now U.S. Pat. No. 5,655,032 which was a continuation of application Ser. No. 08/107,366 filed Aug. 17, 1993, now abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (1)
Number |
Date |
Country |
4-26156 |
Jan 1992 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
515385 |
Aug 1995 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
107366 |
Aug 1993 |
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