US 12,069,259 B2
Image coding apparatus, image coding method, and program, and image decoding apparatus, image decoding method, and program
Osamu Kawaguchi, Kanagawa (JP); and Masato Shima, Tokyo (JP)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on Oct. 20, 2022, as Appl. No. 18/048,351.
Application 18/048,351 is a continuation of application No. 17/132,678, filed on Dec. 23, 2020, granted, now 11,523,113.
Application 17/132,678 is a continuation of application No. PCT/JP2019/023715, filed on Jun. 14, 2019.
Prior Publication US 2023/0069664 A1, Mar. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/119 (2014.01); H04N 19/117 (2014.01); H04N 19/169 (2014.01); H04N 19/176 (2014.01); H04N 19/82 (2014.01)
CPC H04N 19/119 (2014.11) [H04N 19/117 (2014.11); H04N 19/176 (2014.11); H04N 19/1883 (2014.11); H04N 19/82 (2014.11)] 6 Claims
OG exemplary drawing
 
1. An image encoding apparatus capable of encoding an image in units of blocks, the image encoding apparatus comprising:
a first splitting unit configured to split an image into a plurality of coding tree units;
a second splitting unit configured to split a coding tree unit into a plurality of blocks;
a comparing unit configured to compare a division value with a threshold for determining a block group to share a quantization parameter, the division value being a value that increases as a number of times the coding tree unit is split increases, the block group being capable of including at least a plurality of blocks of which the division value is greater than the threshold;
an encoding unit configured to encode data indicating a value of a quantization parameter in accordance with a comparison result obtained by the comparing unit; and
a filtering unit configured to perform deblocking filtering,
wherein, in a case where at least any block included in the block group includes a non-zero coefficient,
the encoding unit is configured to encode first data indicating a first value of a quantization parameter shared in the block group in association with the block including the non-zero coefficient,
wherein, in a case where the block group consists of three blocks and the three blocks included in the block group do not include a non-zero coefficient,
the encoding unit is configured not to encode the first data for the block group, and the filtering unit is configured to perform deblocking filtering on the three blocks included in the block group by using a second value of a quantization parameter which is a value derived by calculating a mean value of quantization parameters for blocks other than the block group, and
wherein the encoding unit is configured to encode, into a bitstream, information for specifying the threshold.