Video encoding method using offset adjustments according to pixel classification and apparatus therefor, video decoding method and apparatus therefor

A video decoding apparatus comprising:

• a parser which is configured to parse, from a bitstream, offset merge information indicating whether an offset parameter of a current block is determined according to an offset parameter of a neighboring block;
• and
• an offset compensator which configured to compensating for samples of the current block by using the offset parameter of the current block,
• wherein:
• when the offset merge information indicates that the offset parameter of the current block is determined according to the offset parameter of the neighboring block, the offset compensator is configured to determine the offset parameter of the current block using the offset parameter of the neighboring block,
• when the offset merge information indicates that the offset parameter of the current block is not determined according to the offset parameter of the neighboring block, the parser is configured to obtain, from the bitstream, offset type information,
• when the offset type information indicates a band offset type, the parser is configured to obtain, from the bitstream, absolute values of a plurality of offset values, and, when the absolute values of the plurality of offset values are not zero, further obtain sign bits of the plurality of offset values from the bitstream, and the offset compensator is configured to compensate for samples of the current block by using the absolute values of the plurality of offset values and the sign bits of the plurality of offset values, and
• the neighboring block is one of a left block and an upper block adjacent to the current block.