Distributed intraframe transmission in digital video compression

• US 20020106023A1
• Filed: 02/07/2001
• Published: 08/08/2002
• Est. Priority Date: 02/07/2001
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: OʼNeill, Thomas
• Granted Patent: US 6,868,122 B2
• Time in Patent Office: Days
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

The present invention provides a method and apparatus for distributed intraframe transmission. In one embodiment of the present invention, digital images are divided into regions. In this embodiment, an I-frame is not transmitted all at once. Instead, in each transmission, a region of the image is compressed without using interframe compression while the rest of the image is compressed using interframe compression. The region transmitted without interframe compression changes with each transmission. Thus, over the course of several transmissions every region of the image is transmitted without interframe compression. A transmission schedule controls the transmission of I-frame data for an entire image over the course of several frame transmissions. In one embodiment, a digital image is divided into M regions, and one region is transmitted without using interframe compression in each frame. In one embodiment, the M regions are numbered from 0 to M−1, and a region is selected for transmission without using interframe compression when the region number is equal to MOD (F, M), where F is the frame number. In one embodiment, the regions are non-overlapping rectangular regions. In another embodiment, the regions are strips of pixels. In another embodiment, regions are non-contiguous pixels. In yet another embodiment, regions which will be transmitted without interframe compression comprise sets of pixels which have not been refreshed within M frames and pixels which are selected by a compressibility criteria.

Claims

1. A method of intraframe transmission comprising:

dividing a digital image into a plurality of regions;

selecting a first region wherein said first region is encoded without interframe compression; and

transmitting said regions.

2. The method of claim 1 wherein said regions comprise:

a non-overlapping rectangular group of pixels.

3. The method of claim 1 wherein said regions comprise:

a strip of pixels.

4. The method of claim 1 wherein said regions comprise:

a plurality of non-contiguous pixel groups.

5. The method of claim 1 wherein said step of selecting comprises:

determining one or more first groups of pixels wherein intraframe compression of said first groups results in better compression than interframe compression; and

determining one or more second groups of pixels wherein said second groups were not encoded without interframe compression within a number of transmissions.

6. The method of claim 1 wherein said step of selecting comprises:

assigning a first number to a first pixel group; and

selecting said first pixel group to be included in said first region for a transmission wherein said transmission is associated with a second number and said second number modulo a third number is equal to said first number wherein said third number is a total number of regions.

7. An intraframe transmission unit comprising:

a dividing unit configured to divide an I-frame into a plurality of regions;

a selection unit configured to select a first region wherein said first region is encoded without interframe compression; and

a transmitter configured to transmit said regions.

8. The intraframe transmission unit of claim 7 wherein said regions comprise:

a non-overlapping rectangular group of pixels.

9. The intraframe transmission unit of claim 7 wherein said regions comprise:

a strip of pixels.

10. The intraframe transmission unit of claim 7 wherein said regions comprise:

a plurality of non-contiguous pixel groups.

11. The intraframe transmission unit of claim 7 wherein said selection unit comprises:

a first determiner configured to determine one or more first groups of pixels wherein intraframe compression of said first groups results in better compression than interframe compression; and

a second determiner configured to determine one or more second groups of pixels wherein said second groups were not encoded without interframe compression within a number of transmissions.

12. The intraframe transmission unit of claim 7 wherein said selection unit comprises:

a labeler configured to assign a first number to a first pixel group; and

a second selection unit configured to select said first pixel group to be included in said first region for a transmission wherein said transmission is associated with a second number and said second number modulo a third number is equal to said first number wherein said third number is a total number of regions.

14. The computer program product of claim 13 wherein said regions comprise:

a non-overlapping rectangular group of pixels.

15. The computer program product of claim 13 wherein said regions comprise:

a strip of pixels.

16. The computer program product of claim 13 wherein said regions comprise:

a plurality of non-contiguous pixel groups.

17. The computer program product of claim 13 wherein said computer readable code configured to cause a computer to select comprises:

computer readable code configured to cause a computer to determine one or more first groups of pixels wherein intraframe compression of said first groups results in better compression than interframe compression; and

computer readable code configured to cause a computer to determine one or more second groups of pixels wherein said second groups were not encoded without interframe compression within a number of transmissions.

18. The computer program product of claim 13 wherein said computer readable code configured to cause a computer to select comprises:

computer readable code configured to cause a computer to assign a first number to a first pixel group; and

computer readable code configured to cause a computer to select said first pixel group to be included in said first region for a transmission wherein said transmission is associated with a second number and said second number modulo a third number is equal to said first number wherein said third number is a total number of regions.

13. A computer program product comprising:

a computer usable medium having computer readable program code embodied therein configured for intraframe transmission, comprising;

computer readable code configured to cause a computer to divide an I-frame into a plurality of regions;

computer readable code configured to cause a computer to select a first region wherein said first region is encoded without interframe compression; and

computer readable code configured to cause a computer to transmit said regions.