Signal data processing using equal importance packetization

• US 6,215,787 B1
• Filed: 03/24/1998
• Issued: 04/10/2001
• Est. Priority Date: 10/24/1997
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Ng, Francis Man Lung, Kovacevic, Jelena
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): JONES, PRENELL P
• Application Number:
  US09/047,267
• Time in Patent Office: 1,113 Days
• Field of Search: 370/389, 370/422, 370/474, 370/477, 370/468, 455/303, 455/306, 375/240, 375/216, 375/260, 375/206, 348/17
• US Class Current: 370/389
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/65 using error resilience
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467

Abstract

The invention provides improved processing of image data and other types of signal data by representing the signal data in such a way that, when separated into packets, all packets are of approximately the same importance. As a result, if some of the packets are, for example, randomly lost in a lossy packet network, the resulting degradation in a reconstructed version of the signal is substantially uniform regardless of which packets are lost. A given image or other signal may be separated into packets using an energy equalization process, a signal whitening process, or other suitable technique. The invention may be utilized in conjunction with data transmission over a wide variety of lossy packet networks, and may be used with raw or compressed image data, as well as video, audio, speech and other types of signal data. Moreover, the invention can be used to facilitate the processing of signal data in multiresolution storage applications.

Claims

1. A method of processing a signal, comprising the steps of:

separating the signal into a plurality of portions; and

assigning the portions of the signal to packets, such that a reconstructed version of the signal generated from a given subset of the packets will have substantially the same signal quality regardless of which of the packets are in the subset.

2. The method of claim 1 wherein the signal is a compressed or uncompressed image signal.

3. The method of claim 1 wherein the signal is a compressed or uncompressed video signal.

4. The method of claim 1 wherein the signal is a compressed or uncompressed audio signal.

5. The method of claim 1 wherein the signal is a compressed or uncompressed speech signal.

6. The method of claim 1 wherein the separating and assigning steps further include:

separating the signal into a plurality of subbands; and

assigning the subbands to the packets in accordance with an energy equalization algorithm such that the cumulative signal energies of the packets are substantially equal.

7. The method of claim 1 wherein the separating and assigning steps further include:

whitening the signal to produce a whitened signal;

separating the whitened signal into a plurality of subbands; and

assigning the subbands to the packets deterministically.

8. The method of claim 1 wherein the separating and assigning steps are applied to the signal in an uncompressed form, and the method further includes the step of individually compressing one or more of the packets.

9. The method of claim 1 further including the step of storing the packets in a storage device in the form of a plurality of files each suitable for generating a reconstructed version of the signal at substantially the same resolution.

10. An apparatus for processing a signal, the apparatus comprising:

a filter bank for separating the signal into a plurality of portions; and

a packetizer for assigning the portions of the signal to packets, such that a reconstructed version of the signal generated from a given subset of the packets will have substantially the same signal quality regardless of which of the packets are in the subset.

11. The apparatus of claim 10 wherein the filter bank is operative to separate a compressed or uncompressed image signal into a plurality of portions.

12. The apparatus of claim 10 wherein the filter bank is operative to separate a compressed or uncompressed video signal into a plurality of portions.

13. The apparatus of claim 10 wherein the filter bank is operative to separate a compressed or uncompressed audio signal into a plurality of portions.

14. The apparatus of claim 10 wherein the filter bank is operative to separate a compressed or uncompressed speech signal into a plurality of portions.

15. The apparatus of claim 10 wherein the packetizer comprises an energy equalization device which assigns the subbands of the signal to packets, such that the cumulative signal energies of the packets are approximately equal.

16. The apparatus of claim 10 further including a signal whitening device for whitening the signal, and wherein the filter bank separates the whitened signal into a plurality of subbands.

17. The apparatus of claim 10 wherein the filter bank and packetizer process the signal in an uncompressed form, and the apparatus further includes an encoder for individually compressing one or more of the packets.

18. The apparatus of claim 10 further including a storage device for storing the packets in the form of a plurality of files each suitable for generating a reconstructed version of the signal at substantially the same resolution.