Method of encoding/decoding of multiview video sequence based on adaptive compensation of local illumination mismatches at interframe prediction

A method of encoding a multiview video sequence based on adaptive compensation of a local illumination mismatch in inter-frame prediction, an encoded frame being represented as a set of non-overlapping areas of pixels used as units of coding, and the method being performed by a computer system and comprising:

• selecting a current encoded block belonging to a current coding unit;
• determining a reference block in a reference frame, the reference block being used for generation of block-prediction for the current encoded block, and pixels of the reference block being already completely encoded and decoded;
• computing a correction parameter used to correct a change in illumination of the reference block;
• correcting the illumination, by adjusting values of all pixels of the reference block, based on the determined correction parameter;
• generating the block-prediction for the current encoded block, using the reference block with the corrected illumination;
• and
• decoding the current encoded block, through the generated block-prediction,
• wherein a procedure comprising the computing of the correction parameter and the correcting of the illumination comprises:
• obtaining values of pixels restored by encoding and then decoding, from a vicinity of the current encoded block of the encoded frame, and from a vicinity of the reference block;
• excluding from consideration a pixel included in the vicinity of the current encoded block and a pixel included in the vicinity of the reference block, the pixels being estimated to be unreliable for computation of the correction parameter used to correct the change in the illumination by at least one preset criterion;
• computing the correction parameter, based on an initial value and using only a reliable pixel;
• and
• estimating a change in values of pixels of the reference block,
• wherein, when the change is estimated to be essential, the values of the pixels of the reference block are corrected using the computed correction parameter.

A method of decoding a multiview video sequence based on adaptive compensation of a local illumination mismatch in inter-frame prediction, a decoded frame being represented as a set of non-overlapping areas of pixels used as units of coding, and the method being performed by a computer system and comprising:

• selecting a current decoded block belonging to a current coding unit;
• determining a reference block for the current decoded block, the reference block being included in a reference frame;
• computing a correction parameter used to correct a change in illumination of the determined reference block;
• correcting the illumination, by adjusting values of all pixels of the reference block, based on the determined correction parameter;
• generating a block-prediction for the current decoded block, using the reference block with the corrected illumination;
• and
• decoding the current decoded block through the generated block-prediction,
• wherein a procedure comprising the computing of the correction parameter and the correcting of the illumination comprises:
• obtaining values of pixels restored by encoding and then decoding, from a vicinity of the current decoded block of the decoded frame, and from a vicinity of the reference block;
• excluding from consideration a pixel included in the vicinity of the current decoded block and a pixel included in the vicinity of the reference block, the pixels being estimated to be unreliable for computation of the correction parameter used to correct the change in the illumination by at least one preset criterion;
• computing the correction parameter, based on found numerical ratios considering an initial value;
• and
• correcting values of pixels of the reference block, using the computed correction parameter, when a change in the values of the pixels of the reference block is estimated to be essential.