Header compression for image data stream

• US 20030081838A1
• Filed: 05/31/2001
• Published: 05/01/2003
• Est. Priority Date: 05/31/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: WebEx Communications Incorporated (Cisco Systems, Inc.)
• Inventors: Teng, Chia-Yuan
• Granted Patent: US 6,816,616 B2
• Time in Patent Office: Days
• US Class Current: 382/232
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/463 by compressing encoding parameters before transmission
• CPC Class Codes: H04N 19/60 using transform coding

Abstract

Headers of image frames are compressed. Header of a first frame is received, where the header includes a plurality of header parameters. Further, differences are determined between the header parameters and a plurality of default parameters, and non-default parameters are sent when there are differences. The header is then compressed to include only a first type of marker, and is sent through the transmission channel. In one embodiment, the non-default parameters are sent through a control channel, while the compressed header is sent through a data channel.

Claims

1. A method for compressing headers of image frames, comprising:

receiving a header of a first frame, said header including a plurality of header parameters;

determining whether there are differences between the header parameters and a plurality of default parameters;

first sending non-default parameters when there are differences;

compressing said header to include only a first type of marker; and

second sending said compressed header.

2. The method of claim 1, wherein said image frames include frames coded in JPEG2000.

3. The method of claim 2, wherein the plurality of header parameters includes information about image and tiles, including image size (width and height), tile size, number of components, component transforms used, wavelet transform used, component precision, number of decomposition levels, color/depth, number of layers, code-block size, quantization, coding styles (e.g. selective arithmetic coding bypass and/or vertically stripe causal context) or some combinations of these parameters.

4. The method of claim 1, further comprising:

designating the differences in the header parameters as non-default parameters.

5. The method of claim 1, wherein said first sending non-default parameters uses a control channel.

6. The method of claim 5, wherein said control channel includes a Real-time Streaming Protocol (RTSP).

7. The method of claim 1, wherein said second sending said compressed header uses a data channel.

8. The method of claim 7, wherein said data channel includes a User Datagram Protocol (UDP).

9. The method of claim 1, wherein said first type of marker includes a one-byte marker.

10. The method of claim 9, wherein the one-byte marker has a hex value 0x00.

11. The method of claim 1, further comprising:

receiving a second header of a frame subsequent to the first frame, said second header including a second plurality of header parameters;

determining whether there are differences between the second plurality of header parameters and a previous plurality of header parameters;

first compressing said second header to include only a first type of marker when there are no differences;

second compressing said second header to include a second type of marker, and a group of parameters that are different, when there are differences; and

sending said compressed second header.

12. A method for compressing headers of image frames, comprising:

receiving a header of a current frame subsequent to a first frame, said header including a plurality of header parameters;

determining whether there are differences between the plurality of header parameters and a previous plurality of header parameters;

first compressing said header to include only a first type of marker when there are no differences;

second compressing said header to include a second type of marker, and a group of parameters that are different, when there are differences; and

sending said compressed header.

13. The method of claim 12, wherein the group of parameters includes parameters having information about image and tiles, including image size (width and height), tile size, number of components, component transforms used, wavelet transform used, component precision, subsampling factor, number of decomposition levels, color/depth, number of layers, code-block size, coding styles (e.g. selective arithmetic coding bypass and vertically stripe causal context), quantization, or some combinations of these parameters.

14. The method of claim 12, wherein said second type of marker includes a one-byte non-zero marker.

15. The method of claim 14, wherein each bit of the first and second type of marker indicates a presence of certain image parameters.

16. The method of claim 14, wherein size of said compressed header is derived from the first and second type of marker.

17. The method of claim 12, wherein said sending said compressed header uses a data channel.

18. The method of claim 12, wherein said previous plurality of header parameters includes header parameters from frames prior to the current frame.

19. A computer readable medium containing executable instructions which, when executed in a processing system, causes the system to perform header compression, comprising:

receiving a header of a first frame, said header including a plurality of header parameters;

determining whether there are differences between the header parameters and a plurality of default parameters;

first sending non-default parameters when there are differences;

compressing said header to include only a first type of marker; and

second sending said compressed header.

20. The computer readable medium of claim 19, further comprising:

receiving a second header of a frame subsequent to the first frame, said second header including a second plurality of header parameters;

determining whether there are differences between the second plurality of header parameters and a previous plurality of header parameters;

first compressing said second header to include only a first type of marker when there are no differences;

second compressing said second header to include a second type of marker, and a group of parameters that are different when there are differences; and

sending said compressed second header.

21. A computer readable medium containing executable instructions which, when executed in a processing system, causes the system to perform header compression, comprising:

receiving a header of a current frame subsequent to a first frame, said header including a plurality of header parameters;

determining whether there are differences between the plurality of header parameters and a previous plurality of header parameters;

first compressing said header to include only a first type of marker when there are no differences;

second compressing said header to include a second type of marker, and a group of parameters that are different when there are differences; and

sending said compressed header.

22. The computer readable medium of claim 21, wherein said previous plurality of header parameters includes header parameters from frames prior to the current frame.