CPC H04N 19/132 (2014.11) [H04N 19/159 (2014.11); H04N 19/186 (2014.11); H04N 19/46 (2014.11)] | 9 Claims |
1. A moving image decoding device for generating a prediction image by using an intra-frame prediction mode, the moving image decoding device comprising:
at least one processor; and
at least one storage device coupled to the at least one processor and storing computer- executable instructions which, when executed by the at least one processor, cause the moving image decoding device to:
derive a first parameter and a second parameter by using a sampled luminance value downsampled according to a chrominance format and the intra-frame prediction mode; and
derive the prediction image by using the first parameter and the second parameter, wherein:
the first parameter is derived by
deriving a logarithmic value of a luminance difference value,
deriving a first value by right-shifting a second value related to the luminance difference value by the logarithmic value, and
using a third value acquired by multiplying a fourth value by a chrominance difference value, wherein the fourth value is determined from a reference table by using the first value, and
the second parameter is derived by using the first parameter.
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