CPC H04N 19/593 (2014.11) [H04N 19/105 (2014.11); H04N 19/186 (2014.11); H04N 19/80 (2014.11)] | 5 Claims |
1. A prediction image generation apparatus for generating a prediction image by using an intra prediction parameter including a Cross-Component Linear Model (CCLM) prediction mode, the prediction image generation apparatus comprising:
CCLM prediction parameter circuitry that derives:
(i) a first difference value, which is a difference between chrominance values,
(ii) a first variable by using (a) a second difference value, which is a difference between luminance values, (b) a first logarithmic value derived by using the second difference value, and (c) a right shift operation,
(iii) a shift value by using a second logarithmic value derived by using an absolute value of the first difference value, and
(iv) a CCLM prediction parameter by using (a) the first variable, (b) the first difference value, and (c) the shift value; and
a CCLM prediction filter that derives the prediction image by using the CCLM prediction parameter,
wherein
the CCLM prediction parameter is derived by right shifting a second variable by the shift value, wherein the second variable is a sum of a third variable and a value of a rounding parameter, wherein the third variable is a product of (i) the first difference value and (ii) a value, in a reference table, defined by using the first variable.
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