Method and apparatus for video coding

An apparatus, comprising:

• processing circuitry configured to:
• decode prediction information of a current block in a current picture that is a part of a coded video sequence, the prediction information indicating a mapping relationship between each of a plurality of combinations of processed reconstructed samples of a first color component and corresponding output values applied by a cross-component sample offset filter process to a second color component different from the first color component;
• perform the cross-component sample offset filter process based on a first combination of the processed reconstructed samples of the first color component of the current block, the first combination of the processed reconstructed samples of the first color component not being included in the plurality of combinations of the processed reconstructed samples indicated in the prediction information;
• determine an output value of the cross-component sample offset filter process based on one of a default value, a predicted output value predicted from an output offset value applied to a different picture, a different slice, or a different coding block, or one of the output values indicated in the prediction information;
• and reconstruct the current block by applying the determined output value through the cross-component sample offset filter process to reconstructed samples of the second color component of the current block, wherein each of the processed reconstructed samples of the first color component in the first combination is an opposite number of a corresponding processed reconstructed sample in one of the plurality of combinations of processed reconstructed samples indicated in the prediction information, and the one of the output values indicated in the prediction information corresponds to the one of the plurality of combinations of processed reconstructed samples indicated in the prediction information;
• wherein a sum of an index of a
• combination of the processed reconstructed samples of the first color component in a mapping table describing the mapping relationship and an index of a corresponding one of the output values indicated in the mapping table is equal to a maximum index of the mapping table.

A non-transitory computer-readable storage medium storing instructions which, when executed by at least one processor, cause the at least one processor to perform:

• decoding prediction information of a current block in a current picture that is a part of a coded video sequence, the prediction information indicating a mapping relationship between each of a plurality of combinations of processed reconstructed samples of a first color component and corresponding output values applied by a cross-component sample offset filter process to a second color component different from the first color component;
• performing the cross-component sample offset filter process based on a first combination of the processed reconstructed samples of the first color component of the current block, the first combination of the processed reconstructed samples of the first color component not being included in the plurality of combinations of the processed reconstructed samples indicated in the prediction information;
• determining an output value of the cross-component sample offset filter process based on one of a default value, a predicted output value predicted from an output offset value applied to a different picture, a different slice, or a different coding block, or one of the output values indicated in the prediction information;
• and reconstructing the current block by applying the determined output value through the cross-component sample offset filter process to reconstructed samples of the second color component of the current block, wherein each of the processed reconstructed samples of the first color component in the first combination is an opposite number of a corresponding processed reconstructed sample in one of the plurality of combinations of processed reconstructed samples indicated in the prediction information, and the one of the output values indicated in the prediction information corresponds to the one of the plurality of combinations of processed reconstructed samples indicated in the prediction information;
• wherein a sum of an index of a combination of the processed reconstructed samples of the first color component in a mapping table describing the mapping relationship and an index of a corresponding one of the output values indicated in the mapping table is equal to a maximum index of the mapping table.