Granted Patent B2

US 12,192,531 · App. 18/479,663 · Granted Jan 7, 2025

Inventors: Jing Ya Li (Singapore, SG); Han Boon Teo (Singapore, SG); Chong Soon Lim (Singapore, SG); Hai Wei Sun (Singapore, SG); Che-Wei Kuo (Singapore, SG); Chu Tong Wang (Singapore, SG); Tadamasa Toma (Osaka, JP); Takahiro Nishi (Nara, JP); Kiyofumi Abe (Osaka, JP); Yusuke Kato (Osaka, JP)

Assignee: PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA

H04N19/82H04N19/107H04N19/176H04N19/186

Abstract

Claims (20)

1. A decoder comprising:

memory; and

a processor coupled to the memory and configured to:

generate a first coefficient value by applying a CCALF (cross component adaptive loop filtering) process to a first reconstructed image sample of a luma component;

clip the first coefficient value such that the clipped first coefficient value is within a first range from −2 7 to 2 7 -1, the clipped first coefficient value being set to zero in response to the first coefficient value being less than 64;

generate a second coefficient value by applying an ALF (adaptive loop filtering) process to a second reconstructed image sample of a chroma component;

clip the second coefficient value such that the clipped second coefficient value is within a second range different from the first range;

generate a third coefficient value by adding the clipped first coefficient value to the clipped second coefficient value; and

generate a third reconstructed image sample of the chroma component using the third coefficient value.

2. A decoding method comprising:

generating a first coefficient value by applying a CCALF (cross component adaptive loop filtering) process to a first reconstructed image sample of a luma component;

clipping the first coefficient value such that the clipped first coefficient value is within a first range from −2 7 to 2 7 -1, the clipped first coefficient value being set to zero in response to the first coefficient value being less than 64;

generating a second coefficient value by applying an ALF (adaptive loop filtering) process to a second reconstructed image sample of a chroma component;

clipping the second coefficient value such that the clipped second coefficient value is within a second range different from the first range;

generating a third coefficient value by adding the clipped first coefficient value to the clipped second coefficient value; and

generating a third reconstructed image sample of the chroma component using the third coefficient value.

3. A non-transitory computer readable medium storing a bitstream, the bitstream comprising clip information according to which a decoder performs a CCALF (cross component adaptive loop filtering) process and an ALF (adaptive loop filtering) process on a first reconstructed image sample of a luma component and a second reconstructed image sample of a chroma component, respectively,

in the CCALF process, (i) a first coefficient value being generated and (ii) the first coefficient value being clipped such that the clipped first coefficient value is within a first range from −2 7 to 2 7 -1, the clipped first coefficient value being set to zero in response to the first coefficient value being less than 64,

in the ALF process, (i) a second coefficient value being generated and (ii) the second coefficient value being clipped such that the clipped second coefficient value is within a second range different from the first range,

the clipped first coefficient value being added to the clipped second coefficient value to generate a third coefficient value, the third coefficient value being used to generate a third reconstructed image sample of the chroma component.

Continuity (4)

References Cited (45)