Efficient Implementation Of Matrix Based Intra Prediction

Abstract: Apparatus (54) for decoding a predetermined block (18) of a picture using intra-prediction, configured to read, from a data stream (12), a mode index (200) using a binarization code (202). The mode index (200) points to one out of a list (204) of matrix-based intra-prediction modes. The apparatus is configured to predict samples (108) of the predetermined block (18) by computing a matrix-vector product (206) between an input vector (102) derived from reference samples (17) in a neighbourhood of the predetermined block (18) and a prediction matrix (19) associated with the matrix-based intra-prediction mode (k) pointed to by the mode index (200) and associating components (210) of an output vector (208) obtained by the matrix-vector product (206) onto sample positions (104) of the predetermined block. The list (204) of matrix-based intra-prediction modes consists of an even number of matrix-based intra-prediction modes. The list (204) of matrix-based intra-prediction modes consists of pairs (212) of matrix-based intra-prediction modes, and, for each pair (212) of matrix-based intra-prediction modes, the prediction matrix (19) associated with a first matrix-based intra-prediction mode of the respective pair (212) of matrix- based intra-prediction modes is equal to the prediction matrix (19) associated with a second matrix-based intra-prediction mode of the respective pair (212) of matrix-based intra-prediction modes. For each pair (212) of matrix-based intra-prediction modes, the apparatus is configured so that, if the matrix-based intra-prediction mode pointed to by the mode index (200) is the first matrix-based intra-prediction mode of the respective pair (212) of matrix-based intra-prediction modes, an association of the reference samples (17) in the neighbourhood of the predetermined block (18) with components (214) of the input vector (112) and of the sample positions (104) of the predetermined block (18) with the components (210) of the output vector (208) is transposed relative to the association in case of the matrix-based intra-prediction mode pointed to by the mode index (200) being the second matrix-based intra-prediction mode of the respective pair (212) of matrix-based intra-prediction modes. Furthermore, the apparatus is configured to read the mode index (200) using the binarization code (202) from the data stream (12) in a manner so that for each pair (212) of matrix-based intra-prediction modes the first matrix-based intra- prediction mode is assigned a first codeword and the second matrix-based intra-prediction mode is assigned a second codeword and both codewords are equal in length.

Patent Information

Application #

Filing Date

21 March 2022

Publication Number

10/2024

Publication Type

INA

Invention Field

COMMUNICATION

Status

Email

Parent Application

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