公开(公告)号：CA2326785A1

公开(公告)日：2001-06-02

申请号：CA2326785

申请日：2000-11-22

Applicant: LUCENT TECHNOLOGIES INC

Inventor： YANG KYEONG HO ,  FARYAR ALIREZA FARID ,  SEN MOUSHUMI

IPC: H03M7/30 ,  H04N7/26 ,  H04N7/30 ,  H04N19/593

Abstract: A method for use in a block transform-based coding system of processing (e.g ., encoding and/or decoding) one or more block transform coefficients associate d with at least one block of visual data (e.g., an image and/or video sequence) comprises th e following steps. First, one or more previously reconstructed block transform coefficients associated with the visual data are identified. Then, a context selection value is computed for use in processing a block transform coefficient associated with the at least one block, the context selection value being based on the one or more previously reconstructed bloc k transform coefficients. The context selection value may be computed as a function of o ne or more values respectively associated with one or more previously reconstructed blo ck transform coefficients in near proximity, with respect to a scanning order, to the blo ck transform coefficient to be processed. Further, the context selection value may be computed as a function of a spatial frequency associated with the block transform coefficient. Still further, the context selection value may be computed as a function of both the one or more values respectively associated with the one or more previously reconstructed block transform coefficients in near scanning order proximity and the spatial frequency associated with the block transform coefficient.

公开(公告)号：CA2348238C

公开(公告)日：2005-03-01

申请号：CA2348238

申请日：2001-05-23

Applicant: LUCENT TECHNOLOGIES INC

Inventor： SEN MOUSHUMI ,  YANG KYEONG HO ,  FARYAR ALIREZA FARID

IPC: H03M7/30 ,  H04N7/26 ,  H04N7/30

Abstract: Methods and apparatus for performing near lossless-concatenated N-level constrained quantization Hadamard transform decoding are provided. Accordingly, the present invention provides a transform-based coding technique, where the coding loss introduced during repeated encoding and decoding is reduced to a substantial ly insignificant level. This is accomplished by employing a constrained quantization and inverse quantization operation in each level of encoding/decoding in the decoder. In this manner, the concatenation error between each level of a decoder is reduced to a substantially minimum level and the quantization error introduced during quantization operations, i.e., originally at the encoder and in each level of the decoder, is substantially reduced. Thus, the decoded bit stream that is output at the N-th level of the decoder is substantially the same as the original bit stream provided to the input of the encoder.

公开(公告)号：DE60100026T2

公开(公告)日：2003-04-30

申请号：DE60100026

申请日：2001-05-22

Applicant: LUCENT TECHNOLOGIES INC

Inventor： FARYAR ALIREZA FARID ,  SEN MOUSHUMI ,  YANG KYEONG HO

IPC: H03M7/30 ,  H04N7/26 ,  H04N7/30

Abstract: Methods and apparatus for performing near lossless-concatenated N-level constrained quantization Hadamard transform decoding are provided. Accordingly, the present invention provides a transform-based coding technique, where the coding loss introduced during repeated encoding and decoding is reduced to a substantially insignificant level. This is accomplished by employing a constrained quantization and inverse quantization operation in each level of encoding/decoding in the decoder. In this manner, the concatenation error between each level of a decoder is reduced to a substantially minimum level and the quantization error introduced during quantization operations, i.e., originally at the encoder and in each level of the decoder, is substantially reduced. Thus, the decoded bit stream that is output at the N-th level of the decoder is substantially the same as the original bit stream provided to the input of the encoder.