| CPC H04N 19/105 (2014.11) [H04N 19/117 (2014.11); H04N 19/132 (2014.11); H04N 19/176 (2014.11); H04N 19/82 (2014.11)] | 20 Claims |

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1. A picture component prediction method, applied to a decoder, the method comprising:
determining a first picture component reference value set of a current block;
determining multiple first picture component reference values according to the first picture component reference value set, wherein the multiple first picture component reference values include four reference values corresponding to four preset sample positions, respectively;
performing first filtering processing on sample values of samples corresponding to the multiple first picture component reference values, respectively, to determine multiple filtered first picture reference sample values;
determining a parameter of a component linear model according to the multiple filtered first picture reference sample values and corresponding to-be-predicted picture component reference values, the to-be-predicted picture component being a picture component which is different from the first picture component, and the component linear model characterizing a linear mapping relationship for mapping a sample value of the first picture component to a sample value of the to-be-predicted picture component;
performing mapping processing on a reconstructed value of the first picture component of the current block according to the component linear model to obtain a mapped value; and
determining a predicted value of the to-be-predicted picture component of the current block according to the mapped value;
wherein determining the multiple first picture component reference values according to the first picture component reference value set comprises:
selecting two reference samples from samples in one or more neighboring lines at a top side of the current block according to preset positions, and selecting two reference samples from samples in one or more neighboring columns at a left side of the current block according to preset positions; and
determining the multiple first picture component reference values according to the four selected samples.
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