CODING OF INTRA-PREDICTION MODES
    7.
    发明公开

    公开(公告)号:EP4376407A1

    公开(公告)日:2024-05-29

    申请号:EP23211632.7

    申请日:2020-06-10

    摘要: There are disclosed techniques for block-based predicting a block of a picture efficiently, like an apparatus (3000) for decoding a predetermined block (18) of a picture (10) using intra-prediction, configured to derive a set-selective syntax element (522) from the data stream (12) which indicates whether the predetermined block (18) is to be predicted using one of a first set (508) of intra-prediction modes comprising a DC intra prediction mode (506) and angular prediction modes (500). If the set-selective syntax element (522) indicates that the predetermined block (18) is to be predicted using one of the first set (508) of intra-prediction modes, the apparatus is configured to form a list (528) of most probable intra-prediction modes on the basis of intra-prediction modes (3050) using which neighbouring blocks (524, 526) neighbouring the predetermined block (18) are predicted, derive a MPM list index (534) from the data stream (12) which points into the list (528) of most probable intra-prediction modes onto a predetermined intra-prediction mode (3100) and intra-predict the predetermined block (18) using the predetermined intra-prediction mode (3100). If the set-selective syntax element (522) indicates that the predetermined block (18) is not to be predicted using one of the first set (508) of intra-prediction modes, the apparatus is configured to derive a further index (540; 546) from the data stream (12) which indicates a predetermined matrix-based intra-prediction mode (3200) out of a second set (520) of matrix-based intra-prediction modes (510), compute a matrix-vector product (512) between a vector (514, 400, 402) derived from reference samples (17) in a neighbourhood of the predetermined block (18) and a predetermined prediction matrix (516) associated with the predetermined matrix-based intra-prediction mode (3200) so as to obtain a prediction vector (518), and predict samples of the predetermined block (18) on the basis of the prediction vector (518). The list (528) of most probable intra-prediction modes is formed on the basis of intra-prediction modes (3050) using which neighbouring blocks (524, 526) neighbouring the predetermined block (18) are predicted such that the list (528) of most probable intra-prediction modes is free of the DC intra prediction mode (506) in case of the neighbouring blocks (524, 526) being predicted by any of the angular intra prediction modes (500).