Image encoding method and device, and decoding method and device therefor
A video encoding method and apparatus and a video decoding method and apparatus. In the video encoding method, a first predicted coding unit of a current coding unit that is to be encoded is produced, a second predicted coding unit is produced by changing a value of each pixel of the first predicted coding unit by using each pixel of the first predicted coding unit and at least one neighboring pixel of each pixel, and the difference between the current coding unit and the second predicted coding unit is encoded, thereby improving video prediction efficiency.
1. An apparatus for decoding an image, the apparatus comprising:
a splitter which determines at least one coding unit included in a maximum coding unit by splitting the maximum coding unit according to split information obtained from a bitstream, and obtains at least one prediction unit from a current coding unit;
a predictor which obtains a first prediction value of a current prediction unit by using neighboring pixels of the current prediction unit, and
obtains a second prediction value of pixels located on a top border and a left border of the current prediction unit by using the obtained first prediction value and at least one neighboring pixel,
wherein:
the second prediction value of the current prediction unit is obtained by using the at least one neighboring pixel and a weighted value of the obtained first prediction value, and the second prediction value of a top-left pixel of the current prediction unit is obtained by using a first neighboring pixel located at a same column as the top-left pixel and a second neighboring pixel located at a same row as the top-left pixel,
the image is split into a plurality of maximum coding units, according to information about a maximum size of a coding unit,
the maximum coding unit is hierarchically split into one or more coding units of depths according to the split information,
a coding unit of a current depth is one of rectangular data units split from a coding unit of an upper depth,
when the split information indicates a split for the current depth, the coding unit of the current depth is split into coding units of a lower depth, independently from neighboring coding units, and
when the split information indicates a non-split of the current depth, at least one prediction unit is obtained from the coding unit of the current depth.