Method and apparatus for prediction refinement with optical flow for an affine coded block

A method for performing a prediction refinement with optical flow (PROF) process for a current sub-block of an affine coded block implemented by a coding device, comprising:

• when a plurality of optical flow decision conditions are fulfilled for the affine coded block, performing the PROF process for the current sub-block of the affine coded block to obtain refined prediction sample values of the current sub-block of the affine coded block by
• performing an optical flow processing for the current sub-block of the affine coded block to obtain a delta prediction value of a current sample of the current sub-block;
• and
• obtaining a refined prediction sample value of the current sample based on the delta prediction value of the current sample and a prediction sample value of the current sample of the current sub-block;
• wherein the plurality of optical flow decision conditions comprises:
• first indication information indicating that PROF is enabled for a picture containing the affine coded block or indicating that PROF is enabled for slices associated with a picture containing the affine coded block;
• and
• second indication information indicating partition is applied to the affine coded block.

An apparatus for performing a prediction refinement with optical flow (PROF) process for a current sub-block of an affine coded block, comprising:

• one or more electronic circuits or processors configured to:
• perform, when a plurality of constraint conditions for applying PROF are not fulfilled for the affine coded block, the PROF process for the current sub-block of the affine coded block to obtain refined prediction sample values of the current sub-block of the affine coded block by
• performing an optical flow processing for the current sub-block of the affine coded block to obtain a delta prediction value of a current sample of the current sub-block;
• and
• obtaining a refined prediction sample value of the current sample based on the delta prediction value of the current sample and a prediction sample value of the current sample of the current sub-block;
• wherein the plurality of constraint conditions for applying PROF comprises:
• first indication information indicating that PROF is disabled for a picture containing the affine coded block or indicating that the PROF is disabled for slices associated with a picture containing the affine coded block;
• and
• second indication information indicating no partition of the affine coded block.

An apparatus for performing a prediction refinement with optical flow (PROF) process for a current sub-block of an affine coded block, comprising:

• one or more electronic circuits or processors configured to:
• perform, when a plurality of optical flow decision conditions are fulfilled for the affine coded block, the PROF process for the current sub-block of the affine coded block to obtain refined prediction sample values of the current sub-block of the affine coded block by
• perform an optical flow processing for the current sub-block of the affine coded block to obtain a delta prediction value of a current sample of the current sub-block;
• and
• obtain a refined prediction sample value of the current sample based on the delta prediction value of the current sample and a prediction sample value of the current sample of the current sub-block;
• wherein the plurality of optical flow decision conditions comprises:
• first indication information indicating that PROF is enabled for a picture containing the affine coded block or indicating that PROF is enabled for slices associated with a picture containing the affine coded block;
• and
• second indication information indicating partition is applied to the affine coded block.

A non-transitory computer-readable media storing computer instructions for performing a prediction refinement with optical flow (PROF) process for a current sub-block of an affine coded block, that when executed by one or more processors, cause the one or more processors to perform the operations of:

• when a plurality of constraint conditions for applying PROF are not fulfilled for the affine coded block, performing the PROF process for the current sub-block of the affine coded block to obtain refined prediction sample values of the current sub-block of the affine coded block by
• performing an optical flow processing for the current sub-block of the affine coded block to obtain a delta prediction value of a current sample of the current sub-block;
• and
• obtaining a refined prediction sample value of the current sample based on the delta prediction value of the current sample and a prediction sample value of the current sample of the current sub-block;
• wherein the plurality of constraint conditions for applying PROF comprises:
• first indication information indicating that PROF is disabled for a picture containing the affine coded block or indicating that the PROF is disabled for slices associated with a picture containing the affine coded block;
• and
• second indication information indicating no partition of the affine coded block.

A non-transitory computer-readable media storing computer instructions for performing a prediction refinement with optical flow (PROF) process for a current sub-block of an affine coded block, that when executed by one or more processors, cause the one or more processors to perform the operations of:

• when a plurality of optical flow decision conditions are fulfilled for the affine coded block, performing the PROF process for the current sub-block of the affine coded block to obtain refined prediction sample values of the current sub-block of the affine coded block by
• performing an optical flow processing for the current sub-block of the affine coded block to obtain a delta prediction value of a current sample of the current sub-block;
• and
• obtaining a refined prediction sample value of the current sample based on the delta prediction value of the current sample and a prediction sample value of the current sample of the current sub-block;
• wherein the plurality of optical flow decision conditions comprises:
• first indication information indicating that PROF is enabled for a picture containing the affine coded block or indicating that PROF is enabled for slices associated with a picture containing the affine coded block;
• and
• second indication information indicating partition is applied to the affine coded block.