US 12,262,058 B2
Encoder, decoder, encoding method, and decoding method
Masato Ohkawa, Toyama (JP); Hideo Saitou, Ishikawa (JP); Kiyofumi Abe, Osaka (JP); Takahiro Nishi, Nara (JP); Tadamasa Toma, Osaka (JP); and Yusuke Kato, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA, Torrance, CA (US)
Filed by Panasonic Intellectual Property Corporation of America, Torrance, CA (US)
Filed on Aug. 9, 2023, as Appl. No. 18/231,933.
Application 18/231,933 is a continuation of application No. 17/971,817, filed on Oct. 24, 2022, granted, now 11,770,561.
Application 17/971,817 is a continuation of application No. 17/591,259, filed on Feb. 2, 2022, granted, now 11,533,511, issued on Dec. 20, 2022.
Application 17/591,259 is a continuation of application No. PCT/JP2020/032678, filed on Aug. 28, 2020.
Claims priority of provisional application 62/892,774, filed on Aug. 28, 2019.
Prior Publication US 2023/0388549 A1, Nov. 30, 2023
Int. Cl. H04N 19/112 (2014.01); H04N 19/119 (2014.01); H04N 19/12 (2014.01); H04N 19/16 (2014.01); H04N 19/17 (2014.01); H04N 19/184 (2014.01); H04N 19/186 (2014.01); H04N 19/30 (2014.01); H04N 19/60 (2014.01)
CPC H04N 19/649 (2014.11) [H04N 19/112 (2014.11); H04N 19/119 (2014.11); H04N 19/12 (2014.11); H04N 19/16 (2014.11); H04N 19/17 (2014.11); H04N 19/184 (2014.11); H04N 19/186 (2014.11); H04N 19/30 (2014.11)] 3 Claims
OG exemplary drawing
 
1. An encoder comprising:
circuitry; and
memory coupled to the circuitry, wherein
in operation, the circuitry:
performs a mapping process of Luma Mapping with Chroma Scaling (LMCS), using line segments forming a transform curve, the mapping process being for transforming a first pixel value space applied to a luma display image signal into a second pixel value space applied to a luma encoding process signal, the line segments each corresponding to a different one of sections obtained by partitioning the first pixel value space; and
encodes an image,
in the performing of the LMCS, the circuitry determines the transform curve so that among boundary values in the second pixel value space which are located at boundaries between the line segments, a first value obtained by dividing a boundary value by a base width is not equal to a second value obtained by dividing another boundary value by the base width, the base width being changed according to a bit depth of the image, and
the base width is obtained by dividing a luma range by a constant value, the luma range being represented by the bit depth.