Claims
- 1. A method for coding two coefficients comprising:a) transforming the two coefficients into two pairs of random variables, one random variable in each pair having substantially equal energy as one random variable in the other pair; b) quantizing each of the pairs of random variables; and c) entropy coding each quantized random variable separately.
- 2. The method according to claim 1, further comprising pairing said entropy coded random variables for transmission over a plurality of channels.
- 3. The method according to claim 1, wherein the transforming step further comprises transforming a first coefficient (A) and a second coefficient (B) into a first random variable(C), a second random variable(D), a third random variable (C-perp) and a fourth variable (D-perp) according to the following equations: C=12βA+β2BD=-12βA+β2BC-perp=-β2β σB2σA2+σB2β2A+2β σA2σA2+σB2β2BD-perp=β2β σB2σA2+σB2β2A+2β σA2σA2+σB2β2Bwhere σA2 and σB2 are the variances of A and B β=σAσB×22ρ(1-(1-2-4ρ))2where ρ is a difference between a total transmitted bitrate and a lowest rate that a coder uses to achieve a two channel distortion.
- 4. The method according to claim 3, wherein the random variable D-perp includes information not represented in random variable D.
- 5. The method according to claim 3, wherein the random variable C-perp includes information not represented in random variable C.
- 6. The method according to claim 3, wherein entropy coded random variables C and D contain all information needed to reconstruct coefficients A and B.
- 7. The method according to claim 3, wherein entropy coded random variables C and D are correlated with each other.
- 8. The method according to claim 3, wherein entropy coded random variables C and C-perp are uncorrelated.
- 9. The method according to claim 1, wherein a first pair of random variables (C, D-perp) are jointly quantized and second pair of random variables (D, C-perp) are jointly quantized.
- 10. The method according to claim 1, wherein entropy coded random variables D and D-perp are uncorrelated.
- 11. A method for performing multiple description coding on a block of coefficients, comprising the steps of:a) pairing coefficients within the block of coefficients to form a plurality of coefficient pairs; b) transforming each coefficient pair into a first pair of transformed coefficients and a second pair of transformed coefficients; c) quantizing each of the first and second pair of transformed coefficients; and d) assigning the first and second pair of quantized and transformed coefficients to different channels.
- 12. The method according to claim 11, further comprising the step of:e) entropy encoding each member of the first pair of quantized and transformed coefficients and each member of the second pair of quantized and transformed coefficients separately prior to transmission.
- 13. The method according to claim 11, wherein the step of transforming further comprises transforming each coefficient pair (A, B) into a first transformed coefficient (C) a second transformed coefficient (D), a third transformed coefficient (C-perp) and a fourth transformed coefficient (D-perp) according to the following equations: C=12βA+β2BD=-12βA+β2BC-perp=-β2β σB2σA2+σB2β2A+2β σA2σA2+σB2β2BD-perp=β2β σB2σA2+σB2β2A+2β σA2σA2+σB2β2BC-perp=-β2β σB2σA2+σB2β2A+2β σA2σA2+σB2β2BD-perp=β2β σB2σA2+σB2β2A+2β σA2σA2+σB2β2Bwhere σA and σB are the variances of A and B, and β=σAσB×22ρ(1-(1-2-4ρ))2where ρ is a difference between a total transmitted bitrate and a lowest rate that a coder uses to achieve a two channel distortion.
- 14. The method according to claim 11, wherein the transforming step further comprises transforming each coefficient pair into the first and second transformed coefficients using a unitary transform such that the first and second transformed coefficients have substantially equivalent energy.
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This patent application claims the benefit of U.S. Provisional Application Ser. No. 60/145,937 entitled Multiple Description Coding Communication System, filed Jul. 28, 1999.
This patent application is related to the following commonly assigned U.S. Provisional Patent Application: Method and Apparatus for Accomplishing Multiple Description Coding for Video, U.S. Provisional Application Serial No. 60/145,852, filed Jul. 27, 1999. This patent application is also related to the following commonly assigned U.S. Patent Application: Multiple Description Coding Communication System, U.S. patent application Ser. No. (08/790,416), filed Jan. 3, 1997.
US Referenced Citations (9)
Provisional Applications (1)
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Number |
Date |
Country |
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60/145937 |
Jul 1999 |
US |