US 2002/0176353 A1 · Scalable and perceptually ranked signal coding and decoding

Abstract

A method and system for encoding and decoding an input signal in relation to the most perceptually relevant aspects of the input signal. A two-dimensional (2D) transform is applied to the input signal to produce a magnitude matrix and a phase matrix that can be inverse quantized by a decoder. A first column of coefficients of the magnitude matrix represents a mean spectral density (MSD) function of the input signal. Relevant aspects of the MSD function are encoded at a beginning of a data packet. The MSD function is also processed through a core perception model to determine bit allocation. The matrices are then quantized and priority ordered into a data packet, with the least perceptually relevant information at the end of the packet so that it may be ignored or truncated for scalability to the channel data rate capacity.

Claims36

Dependent claims

A method for encoding a signal for storage or transmission, comprising the steps of:

(a) implementing a two-dimensional transform of the signal, producing a transform matrix having modulation frequency as one dimension;
(b) reducing a dynamic range of the signal;
(c) quantizing and selecting coefficients included in the transform matrix;
and
(d) producing data packets in which the coefficients that have been selected are encoded based upon a desired order of the coefficients, with coefficients that are more perceptually relevant being used first to fill each data packet and coefficients that are less perceptually relevant being handled in one of the following ways:
(i) discarded once an available space in each data packet that is to be stored or transmitted has been filled with the coefficients that are more perceptually relevant;
and
(ii) disposed last within each data packet, so that the coefficients that are less perceptually relevant can subsequently be truncated from the data packet.

5 more elements

A method for encoding data packets with data derived from a perceptual signal, said data packets being stored as originally encoded, or stored in a truncated form, or transmitted in a truncated form over a network at a data rate that may be less than required to transmit non-truncated data packets, comprising the steps of:

(a) applying a two-dimensional transform to the signal to produce a transform matrix having modulation frequency as one dimension;
(b) quantizing a mean spectral density derived from the transform matrix, to produce a quantized mean spectral density;
(c) determining an inverse quantized mean spectral density using the quantized mean spectral density;
(d) deriving bit allocations from the inverse quantized mean spectral density using a perceptual model;
(e) as a function of the bit allocations and the results of the two-dimensional transform, producing quantized components;
and
(f) determining an order in which the perceptual data are loaded into each data packet, based upon the quantized components, wherein data that are perceptually more important are loaded closer to a beginning of the data packet, while data that are perceptually less important are handled in one of the following ways:
(i) loaded closer to an end of each data packet, if the entire data packet is to be stored in a non-truncated form;
and
(ii) eliminated from the data packets, if said data packets are to be stored or transmitted over the network in the truncated form.

7 more elements

Apparatus for encoding data packets to include data derived from a perceptual signal, said data packets being, comprising:

(a) a memory in which a plurality of machine instructions are stored;
(b) a source of a perceptual signal to be encoded into data packets;
(c) a processor coupled in communication with the source of the perceptual signal, and the memory, said processor executing the machine instructions to carry out a plurality of functions, including:
(i) applying a two-dimensional transform to the perceptual signal, producing a transform matrix having modulation frequency as one dimension;
(ii) quantizing a mean spectral density of one component of the transform matrix, to produce a quantized mean spectral density;
(iii) determining an inverse quantized mean spectral density using the quantized mean spectral density;
(iv) deriving bit allocations from the inverse quantized mean spectral density using a perceptual model;
(v) as a function of the bit allocations and the transform matrix, producing quantized components;
and
(vi) determining an order in which the perceptual data are loaded into each data packet, based upon the quantized components, so that data that are perceptually more important are loaded into a beginning of the data packet, while data that are perceptually less important are handled in one of the following ways:
(1) loaded closer to an end of each data packet;
and
(2) eliminated from the data packets.

10 more elements

Dependencies are inferred from the claim text.

Scalable and perceptually ranked signal coding and decoding

Life of this patent

Scalable and perceptually ranked signal coding and decoding

Life of this patent

Abstract

Claims36