US 12,464,122 B2
Adaptive loop filter
Jonathan Taquet, Talensac (FR); Christophe Gisquet, Acigne (FR); Guillaume Laroche, Saint Aubin d'Aubigné (FR); and Patrice Onno, Rennes (FR)
Assigned to Canon Kabushiki Kaisha, Tokyo (JP)
Filed by CANON KABUSHIKI KAISHA, Tokyo (JP)
Filed on May 1, 2024, as Appl. No. 18/652,716.
Application 18/652,716 is a continuation of application No. 17/434,361, granted, now 11,991,353, previously published as PCT/EP2020/055888, filed on Mar. 5, 2020.
Claims priority of application No. 1903187 (GB), filed on Mar. 8, 2019; application No. 1903584 (GB), filed on Mar. 15, 2019; application No. 1908937 (GB), filed on Jun. 21, 2019; and application No. 1919037 (GB), filed on Dec. 20, 2019.
Prior Publication US 2024/0372999 A1, Nov. 7, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/117 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01); H04N 19/46 (2014.01); H04N 19/82 (2014.01)
CPC H04N 19/117 (2014.11) [H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/46 (2014.11); H04N 19/82 (2014.11)] 17 Claims
OG exemplary drawing
 
11. A device for decoding image data from a bitstream, the device comprising:
a decoder which decodes image data from a bitstream; and
an Adaptive Loop Filter which filters image data, the Adaptive Loop Filter comprising:
a data obtainer which, for a slice containing one or more coding tree blocks, obtains data indicating a number of alternative chroma filters for Adaptive Loop Filtering,
wherein the number can be more than one, wherein the data indicating the number of alternative chroma filters available is provided in an adaptation parameter set, and
wherein the adaptation parameter set comprising the data indicating the number of alternative chroma filters is identified in a slice header;
an index obtainer which, for a coding tree block in the slice containing one or more coding tree blocks, obtains an alternative filter index identifying one of the one or more available alternative chroma filters, the number of which is indicated by the data;
a selector which selects the one of the one or more alternative chroma filters identified by the alternative filter index to filter chroma image data in the coding tree block;
a flag obtainer which obtains a flag for the one or more alternative chroma filters, the flag indicating whether a chroma filter is a linear filter or a non-linear filter; and
an indices obtainer which obtains one or more clipping value indices for the one or more alternative chroma filters when the obtained flag indicates that a chroma filter is a non-linear filter.