Method of filter-unit based in-loop filtering

A method for filter-unit based in-loop filtering in a video encoder, the method comprising:

• generating a video bitstream corresponding to compressed video, wherein Filter Unit (FU) based in-loop filtering is used in a reconstruction loop associated with the compressed video, and wherein reconstructed video is partitioned into FUs;
• incorporating a merge flag in the video bitstream for each of the FUs, wherein the merge flag indicates whether said each of the FUs is merged with a neighboring FU;
• incorporating a merge index in the video bitstream if the merge flag indicates that said each of the FUs is merged, wherein said each of the FUs shares filter parameters with the neighboring FU indicated by the merge index;
• incorporating the filter parameters in the video bitstream if the merge flag indicates that said each of the FUs is not merged;
• and
• providing the video bitstream.

An apparatus for filter-unit based in-loop filtering in a video decoder, the apparatus comprising a processor and a memory configured to:

• receive a video bitstream corresponding to compressed video, wherein Filter Unit (FU) based in-loop filtering is allowed in a reconstruction loop associated with the compressed video;
• derive reconstructed video from the video bitstream, wherein the reconstructed video is partitioned into FUs;
• derive a merge flag from the video bitstream liar each of the FUs, wherein the merge flag indicates whether said each of the FUs is merged with a neighboring FU;
• receive a merge index from the video bitstream if the merge flag indicates that said each of the FUs is merged, wherein filter parameters are determined from filter parameters of the neighboring FU indicated by the merge index;
• receive the filter parameters from the video bitstream if the merge flag indicates that said each of the FUs is not merged:
• and
• apply the in-loop filtering to said each of the FUs using the filter parameters.

An apparatus for filter-unit based in-loop filtering in a video encoder, the apparatus comprising a processor and a memory configured to:

• generate a video bitstream corresponding to compressed video, wherein Filter Unit (FU) based in-loop filtering is used in a reconstruction loop associated with the compressed video, and wherein reconstructed video is partitioned into FUs;
• incorporate a merge flag in the video bitstream for each of the FUs, wherein the merge flag indicates whether said each of the FUs is merged with a neighboring FU;
• incorporate a merge index in the video bitstream if the merge flag indicates that said each of the FUs is merged, wherein said each of the FUs shares filter parameters with the neighboring FU indicated by the merge index;
• incorporate the filter parameters in the video bitstream if the merge flag indicates that said each of the FUs is not merged;
• and
• provide the video bitstream.

A non-transitory computer readable medium storing a computer-executable program, the computer-executable program, when executed, causing a video decoder to perform the following steps:

• receiving a video bitstream corresponding to compressed video, wherein Filter Unit (FU) based in-loop filtering is allowed in a reconstruction loop associated with the compressed video;
• deriving reconstructed video from the video bitstream, wherein the reconstructed video is partitioned into FUs;
• deriving a merge flag from the video bitstream for each of the FUs, wherein the merge flag indicates whether said each of the FUs is merged with a neighboring FU;
• receiving a merge index from the video bitstream if the merge flag indicates that said each of the FUs is merged, wherein filter parameters are determined from filter parameters of the neighboring FU indicated by the merge index;
• receiving the filter parameters from the video bitstream if the merge flag indicates that said each of the FUs is not merged;
• and
• applying the in-loop filtering to said each of the FUs using the filter parameters.