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US 12,499,900 B2Granted
Optimised spherical vector quantisation
AssigneeOrange
InventorsStéphane Ragot, Mohamed Yaoumi
Life of this patent
Estimating the term…
Abstract
A method for encoding an input point on an n-dimensional sphere by encoding n−1 spherical coordinates of said input point. The method includes sequential scalar quantization of the n−1 spherical coordinates in order to obtain at most 2n-2 candidates at the end of the sequential scalar quantization of the n−1 coordinates, and subsequently selecting the best candidate which minimizes a distance between the input point and the at most 2n-2 candidates, and determining the separate quantization indices resulting from the sequential scalar quantization of the spherical coordinates of the best candidate and sequentially encoding the separate quantization indices of the best candidate. A corresponding decoding method, an encoding device and a decoding device are also provided.
Claims19
A method performed by a coding device and comprising:
- receiving a multichannel signal;
- coding at least one parameter derived from the multichannel signal, represented by an input point on a sphere of dimension n, carried out by coding n−1 spherical coordinates of this input point so as to define a spherical grid, the coding comprising the following operations:
- a) sequential scalar quantization of the n−1 spherical coordinates, defining a spherical grid, comprising the following for a current spherical coordinate to be coded:
- determining a number of scalar quantization levels for the current spherical coordinate to be coded, on the basis of the previously coded spherical coordinates when the current spherical coordinate to be coded is of index superior to 1;
- scalar quantization of said current spherical coordinate on the basis of said determined number of levels, with, for n−2 coordinates, determination of two closest candidates for the current spherical coordinate to be coded and giving two quantization indices, in order to obtain at most 2n-2 candidates at the end of the sequential scalar quantization of the n−1 coordinates;
- b) selecting a best candidate that minimizes a distance between the input point and the at most 2n-2 candidates, and determining the separate quantization indices resulting from the sequential scalar quantization of said spherical coordinates of said best candidate;
- and
- c) sequential coding of the separate quantization indices of said best candidate;
- and
- transmitting a result of the sequential coding via a communication network.
7 more elements
A decoding method performed by a decoding device and comprising:
- receiving a global quantization index or on n−1 multiplexed indices via a communication network;
- and
- decoding at least one parameter derived from a multichannel signal, represented by an input point on a sphere of dimension n, carried out by decoding n−1 spherical coordinates of this input point, defining a spherical grid, the decoding comprising sequential decoding of the spherical coordinates, based on the global quantization index or on the n−1 multiplexed indices, by way of the following operations:
- determining a number of quantization levels for the spherical coordinate to be decoded on the basis of the previously decoded spherical coordinates when the spherical coordinate to be decoded is of index superior to 1;
- and
- determining separate indices resulting from separate quantization of said spherical coordinates on the basis of the numbers of levels determined, and then obtaining the corresponding spherical coordinates in order to reconstruct a decoded point on the sphere of dimension n.
3 more elements
A coding device comprising:
- a processing circuit configured to:
- receive a multichannel signal;
- code at least one parameter derived from a multichannel signal, represented by an input point on a sphere of dimension n, carried out by coding n−1 spherical coordinates of this input point so as to define a spherical grid, the coding comprising the following operations:
- a) sequential scalar quantization of the n−1 spherical coordinates, defining a spherical grid, comprising the following for a current spherical coordinate to be coded:
- determining a number of scalar quantization levels for the current spherical coordinate to be coded, on the basis of the previously coded spherical coordinates when the current spherical coordinate to be coded is of index superior to 1;
- scalar quantization of said current spherical coordinate on the basis of said determined number of levels, with, for n−2 coordinates, determination of two closest candidates for the current spherical coordinate to be coded and giving two quantization indices, in order to obtain at most 2n-2 candidates at the end of the sequential scalar quantization of the n−1 coordinates;
- b) selecting a best candidate that minimizes a distance between the input point and the at most 2n-2 candidates, and determining the separate quantization indices resulting from the sequential scalar quantization of said spherical coordinates of said best candidate;
- and
- c) sequential coding of the separate quantization indices of said best candidate;
- and
- transmit a result of the sequential coding via a communication network.
8 more elements
A decoding device comprising:
- a processing circuit configured to:
- receive a global quantization index or on n−1 multiplexed indices via a communication network;
- and
- decode at least one parameter derived from a multichannel signal, represented by an input point on a sphere of dimension n, carried out by decoding n−1 spherical coordinates of this input point, defining a spherical grid, the decoding comprising sequential decoding of the spherical coordinates, based on the global quantization index or on the n−1 multiplexed indices, by way of the following operations:
- determining a number of quantization levels for the spherical coordinate to be decoded on the basis of the previously decoded spherical coordinates when the spherical coordinate to be decoded is of index superior to 1;
- and
- determining separate indices resulting from separate quantization of said spherical coordinates on the basis of the numbers of levels determined, and then obtaining the corresponding spherical coordinates in order to reconstruct a decoded point on the sphere of dimension n.
4 more elements
A non-transitory storage medium able to be read by a processor and storing a computer program comprising instructions for executing a coding method when the instructions are executed by the processor, wherein the coding method comprises:
- receiving a multichannel signal;
- coding at least one parameter derived from a multichannel signal, represented by an input point on a sphere of dimension n, carried out by coding n−1 spherical coordinates of this input point so as to define a spherical grid, the coding comprising the following operations:
- a) sequential scalar quantization of the n−1 spherical coordinates, defining a spherical grid, comprising the following for a current spherical coordinate to be coded:
- determining a number of scalar quantization levels for the current spherical coordinate to be coded, on the basis of the previously coded spherical coordinates when the current spherical coordinate to be coded is of index superior to 1;
- scalar quantization of said current spherical coordinate on the basis of said determined number of levels, with, for n−2 coordinates, determination of two closest candidates for the current spherical coordinate to be coded and giving two quantization indices, in order to obtain at most 2n-2 candidates at the end of the sequential scalar quantization of the n−1 coordinates;
- b) selecting a best candidate that minimizes a distance between the input point and the at most 2n-2 candidates, and determining the separate quantization indices resulting from the sequential scalar quantization of said spherical coordinates of said best candidate;
- and
- c) sequential coding of the separate quantization indices of said best candidate;
- and
- transmitting a result of the sequential coding via a communication network.
7 more elements
Dependencies are inferred from the claim text.