Image encoding/decoding method using prediction block and apparatus for same

A video encoding apparatus comprising:

• a prediction block generating unit to generate a prediction block by performing prediction on a current block based on an intra prediction mode of the current block;
• and
• a reconstructed block generating unit to generate a reconstructed block based on the prediction block and a reconstructed residual block corresponding to the current block,
• wherein the prediction block comprises first prediction pixels and second prediction pixels,
• the first prediction pixels are pixels on a left vertical pixel line,
• the first prediction pixels are filtered based on a first offset when the intra prediction mode of the current block is a vertical mode,
• the second prediction pixels are pixels on an upper horizontal pixel line,
• the second prediction pixels are filtered based on a second offset when the intra prediction mode of the current block is a horizontal mode,
• the left vertical pixel line is one vertical pixel line positioned at a leftmost side of the current block, and
• the upper horizontal pixel line is one horizontal pixel line positioned at an uppermost side of the current block.

A non-transitory computer-readable medium storing a bitstream, the bitstream comprising:

• prediction mode information indicating an intra prediction mode for a current block on which filtering is performed;
• wherein a prediction block is generated by performing prediction on the current block based on the intra prediction mode of the current block which the prediction mode information indicates,
• a reconstructed block is generated based on the prediction block and a reconstructed residual block corresponding to the current block,
• the prediction block comprises first prediction pixels and second prediction pixels,
• the first prediction pixels are pixels on a left vertical pixel line,
• the filtering is performed on the first prediction pixels based on a first offset when the intra prediction mode of the current block is a vertical mode,
• the second prediction pixels are pixels on an upper horizontal pixel line,
• the filtering is performed on the second prediction pixels based on a second offset when the intra prediction mode of the current block is a horizontal mode,
• the left vertical pixel line is one vertical pixel line positioned at a leftmost side of the current block, and
• the upper horizontal pixel line is one horizontal pixel line positioned at an uppermost side of the current block.