Block-based adaptive loop filter (ALF) design and signaling
AssigneeQUALCOMM Incorporated
InventorsMarta Karczewicz, Akshay Gadde, Vadim Seregin, Wei-Jung Chien
Life of this patent
Estimating the term…
Abstract
A video encoder and video decoder may determine a set of adaptive loop filters, from among a plurality of sets of adaptive loop filters, on a per-block basis. Each set of adaptive loop filters may include filters from a previous picture, filters signaled for the current picture, and/or pre-trained filter. By varying the set of adaptive loop filters on a per-block basis, the adaptive loop filters available for each block of video data may be more adapted to local statistics of the video data.
Claims36
A method of coding video data, the method comprising:
- determining, at a slice level, a plurality of sets of adaptive loop filters applicable to a slice;
- determining, at a block level, a set of adaptive loop filters, from among the plurality of sets of adaptive loop filters, for a block of a current picture, wherein the block of the current picture is a coding tree unit (CTU) of the slice, and wherein the set of adaptive loop filters includes a plurality of adaptive loop filters including one or more previous adaptive loop filters and further including a fixed adaptive loop filter;
- and
- adaptive loop filtering the block of the current picture in accordance with the set of adaptive loop filters.
An apparatus configured to code video data, the apparatus comprising:
- a memory configured to store a current picture of video data;
- and
- one or more processors in communication with the memory, the one or more processors configured to:
- determine, at a slice level, a plurality of sets of adaptive loop filters applicable to a slice;
- determine, at a block level, a set of adaptive loop filters, from among the plurality of sets of adaptive loop filters, for a block of the current picture, wherein the block of the current picture is a coding tree unit (CTU) of the slice, and wherein the set of adaptive loop filters includes a plurality of adaptive loop filters including one or more previous adaptive loop filters and further including a fixed adaptive loop filter;
- and
- adaptive loop filter the block of the current picture in accordance with the set of adaptive loop filters.
An apparatus configured to code video data, the apparatus comprising:
- means for determining, at a slice level, a plurality of sets of adaptive loop filters applicable to a slice;
- means for determining, at a block level, a set of adaptive loop filters, from among the plurality of sets of adaptive loop filters, for a block of a current picture, wherein the block of the current picture is a coding tree unit (CTU) of the slice, and wherein the set of adaptive loop filters includes a plurality of adaptive loop filters including one or more previous adaptive loop filters and further including a fixed adaptive loop filter;
- and
- means for adaptive loop filtering the block of the current picture in accordance with the set of adaptive loop filters.
A non-transitory computer-readable storage medium storing instructions that, when executed, cause one or more processors to:
- determine, at a slice level, a plurality of sets of adaptive loop filters applicable to a slice;
- determine, at a block level, a set of adaptive loop filters, from among the plurality of sets of adaptive loop filters, for a block of a current picture, wherein the block of the current picture is a coding tree unit (CTU) of the slice, and wherein the set of adaptive loop filters includes a plurality of adaptive loop filters including one or more previous adaptive loop filters and further including a fixed adaptive loop filter;
- and
- adaptive loop filter the block of the current picture in accordance with the set of adaptive loop filters.
Dependencies are inferred from the claim text.